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SupplementAbsorption.comPreview · grades pending reviewer sign-off

Calcium Absorption: Citrate vs Carbonate

Evidence reviewed by Dr. Colin Reily, PhD · Draft, pending reviewer sign-off · Data built 2026-10-31

Bottom line

Grade AA: well characterized in people. Forms: 5+ human studies, 100+ participants, randomized/crossover designs, consistent values. Comparisons: agreeing head-to-head and matched single-form evidence with clear separation. All grades are drafts pending reviewer sign-off.Draft — pending reviewer review

We found 77 studies with usable absorption data for this supplement, 55 of them in people; every value below is copied from its paper and cited.

Carbonate is the best-characterized form: 16 human studies (total n=369) with measured absorption values (absorption evidence grade A, draft).

Citrate measured higher than carbonate in 7 of 12 human head-to-head studies we have (grade C, draft).

Studies in database
186 (+77 full-text)
Species
183 human, 1 rodent, 2 other animal

Educational information about published research; not medical advice. Not intended to diagnose, treat, cure or prevent any disease. Talk to a clinician before changing supplements, especially if pregnant, nursing or on medication.

On this page

3 of 186 studies are not in humans; each is labeled with a species badge.

Calcium forms compared

Fractional absorption in human studies, by formRange of values as printed (%). Studies used different doses and conditions, so this shows spread, not a ranking.
Citrate malate: 0–59 % (1 study, 64 values; PMIDs 2791301)Citrate malate0–59n=1Carbonate: 18.9–53.6 % (4 studies, 12 values; PMIDs 11528493, 2791301, 38630876, 9771863)Carbonate18.9–53.6n=4059 %
Fractional absorption (%)
FormLowestHighestStudiesPMIDs
Citrate malate058.9812791301
Carbonate18.953.6411528493, 2791301, 38630876, 9771863

n = number of human studies. Full values with doses, sources and citations are in the data tables below.

Calcium forms and studies
FormStudies (abstract screen)Species
Carbonate[PMID 39603923][PMID 40786390][PMID 40617620][PMID 38694695][PMID 37844839][PMID 32302064][PMID 29895376][PMID 28069089][PMID 24170263][PMID 24772062][PMID 24036846][PMID 23411428][PMID 21635154][PMID 19437082][PMID 15734899][PMID 16177199][PMID 14655198][PMID 12680036][PMID 12450902][PMID 12059174][PMID 12412824][PMID 11528493][PMID 11444420][PMID 11274906][PMID 11522558][PMID 11075309][PMID 10579145][PMID 10501794][PMID 9624602][PMID 9129476][PMID 9174467][PMID 8931033][PMID 8602592][PMID 1912761][PMID 1765836][PMID 1984334][PMID 2273192][PMID 2203847][PMID 3213620][PMID 3189218][PMID 3407610][PMID 3614304][PMID 4008614][PMID 4000241][PMID 6707197][PMID 1729463][PMID 20690187]HumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanRodentOther animal
Citrate[PMID 39603923][PMID 37006928][PMID 29895376][PMID 24772062][PMID 22222299][PMID 19437082][PMID 15734899][PMID 12680036][PMID 12412824][PMID 11444420][PMID 11274906][PMID 11075309][PMID 10579145][PMID 10501794][PMID 9624602][PMID 8931033][PMID 7702797][PMID 7706589][PMID 1912761][PMID 1984334][PMID 2042654][PMID 1755399][PMID 2239370][PMID 2296934][PMID 2273192][PMID 3213620][PMID 3654922][PMID 3614304][PMID 4008614][PMID 4000241][PMID 6707197]HumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHumanHuman
Citrate malate[PMID 38694695][PMID 16895892][PMID 15883561][PMID 12450902][PMID 9129476][PMID 9250111][PMID 8505664][PMID 2791301][PMID 8935449]HumanHumanHumanHumanHumanHumanHumanHumanOther animal

Form tags are matched automatically and need reviewer confirmation. Values are not normalized across studies.

Species (abstract screen): 59 human, 1 rodent, 2 other animal
Show 62 studies with verbatim quotes
  • HumanComparison of calcium citrate and calcium carbonate absorption in patients with a Roux-en-Y gastric bypass, sleeve gastrectomy, and one-anastomosis gastric bypass: a double-blind, randomized cross-over trial.
    Surg Obes Relat Dis, 2025 · [PMID 39603923]
    • Key findings · abstract:The intestinal absorption of Ca carbonate and Ca citrate among groups divided by surgical procedure was compared over 8 hours of testing.
    • Key findings · abstract:Measurements included serum and urine Ca concentrations for peak values (Cmax) and area under the curve (AUC0-8h), along with parathyroid hormone (PTH) levels to calculate minimum PTH (PTHmin) and cumulative PTH decline (AUC0-8h).
    • Key findings · abstract:Ca citrate also demonstrated superior relative bioavailability, as evidenced by a higher AUC0-8h of 76.1 mg/dL·h versus 74.7 mg/dL·h for carbonate (P = .001) and a Cmax of 9.8 mg/dL compared to 9.5 mg/dL for carbonate (P < .001[excerpt truncated in our database — see source]
    • +5 more quotes in Studies
  • HumanAbsorption, Scintigraphy, Efficacy and Tolerability of Short-Term Calcium Carbonate Supplementation in Healthy Subjects.
    Cureus, 2025 · [PMID 40786390]
    • Key findings · abstract:Post-dosing, a gradual rise in serum calcium concentration was observed and the peak increment in serum calcium (4.13±0.38 µg/mL) was reached at four hours.
    • Key findings · abstract:The bioavailability, determined as the area under the curve for six hours (ΔAUC0-6) of serum calcium, was 38.2±4.8 µg/mL/hour.
    • Key findings · abstract:An increase in mean serum calcium (~3%) and procollagen type 1 N-terminal propeptide (P1NP) (~13.2%) was observed post-treatment.
    • +3 more quotes in Studies
  • HumanInfluence of concurrent oral calcium carbonate supplementation on steady-state pharmacokinetics of once daily oral raltegravir in persons with HIV: a protocol for a prospective open-label non-randomised study in Canada.
    BMJ Open, 2025 · [PMID 40617620]
    • Cmax · full text, Table 1:ts, blood count, serum creatinine) CD4 and plasma viral load Pregnancy test (urine) PK outcomes Baseline concentration (C0h) Maximum concentration (Cmax) Peak to reach maximum drug concentration (Tmax) Concentration 24 hours post-dose (C24) Minimum concentration (Cmin) Half-life (T1/2) 24 hours area under the concentration-time curve (AUC0-24)
    • Cmax · full text, Section 'Updated recommendation for raltegravir a':According to the product monograph of Isentress HD 1200 mg (2×600 mg) and to the HIV treatment guideline, recommendations are for no co-administration of raltegravir with calcium carbonate.25 Previous work reported a notable decrease in oral absorption, reflected by the reduction in steady-state Cmax AUC0-24, and C24 by 74, 72 and 48% when raltegravir was administered concomitantly with a 3000 mg
    • Tmax · full text, Table 1:a viral load Pregnancy test (urine) PK outcomes Baseline concentration (C0h) Maximum concentration (Cmax) Peak to reach maximum drug concentration (Tmax) Concentration 24 hours post-dose (C24) Minimum concentration (Cmin) Half-life (T1/2) 24 hours area under the concentration-time curve (AUC0-24)
    • +3 more quotes in Studies
  • HumanComparative Evaluation of Bioavailability, Efficacy and Safety of MICROCORE NESC® with Calcium Carbonate and Calcium Citrate Malate in Osteopenic and Osteoporotic Patients: A Randomized Clinical Trial.
    Indian J Orthop, 2024 · [PMID 38694695]
    • Key findings · abstract:Higher percentage of improvement in calcium absorption as depicted by an increase in serum calcium levels (10.23%) in the MICROCORE NESC®-treated group when compared to Shelcal (7.7%) and CCM (7.2%).
    • Key findings · abstract:The relative bioavailability of MICROCORE NESC® with respect to Shelcal was 93%.
    • Relative bioavailability · abstract:The relative bioavailability of MICROCORE NESC® with respect to Shelcal was 93%.
  • HumanBioavailability of calcium in an enriched postbiotic system compared to calcium citrate in healthy postmenopausal females; A randomized, double-blind, comparator-controlled, crossover study.
    Front Nutr, 2023 · n 24 participants · [PMID 37006928]
    • Key findings · abstract:After a 14-h (overnight) fast followed by a single dose of product with a standard low-calcium breakfast, both serum and urine calcium concentrations were assessed for up to 8 and 24 h, respectively.
    • Food effect · abstract:After a 14-h (overnight) fast followed by a single dose of product with a standard low-calcium breakfast, both serum and urine calcium concentrations were assessed for up to 8 and 24 h, respectively.
    • Cmax · full text, Table 2:09) 2.35 (0.08) 2.37 (0.08) iAUC0-8h(mmol/L*h) 0.86 (0.51)a 0.52 (0.45)b 0.60 (0.49)b AUCT0-8h (mmol/L*h) 19.72 (0.74)a 19.34 (0.68)b 19.14 (2.13)a,b Cmax (mmol/L) 2.57 (0.11)a 2.50 (0.10)b 2.54 (0.10)a tmax (h)† 4.0 (2.0–7.0) 4.0 (1.5–8.0) 5.5 (2.0–8.0) Urine Pre-dose urine calcium normalized to creatinine (mmol/mmol) 0.29 (0.19) 0.29 (0.18) 0.30 (0.21) Pre-dose excreted calcium (mg) 5.83 (3.8
    • +10 more quotes in Studies
  • HumanThe Postprandial Calcium Absorption of a Milk-Derived Calcium Permeate - The Acute RENEW Double-Blinded Randomized Controlled Cross-Over Study.
    J Nutr, 2023 · [PMID 37844839]
    • Key findings · abstract:RESULTS: Serum-ionized calcium concentration after the CC supplement was higher at 240 min compared with the CP supplement [between-group difference; 95% confidence interval (CI): 0.039 mmol/L; 95% CI: 0.017-0.061;[excerpt truncated in our database — see source]
    • Key findings · abstract:Serum-ionized calcium concentration after the CC supplement was significantly higher than placebo at all postprandial time points except at 60 min.
    • Key findings · abstract:Urinary calcium concentration in 360 min spot urine was higher after intake of CC compared with CP [between-group difference; 95% CI: 2.47 mmol/L; 95% CI: 1.90-3.03;[excerpt truncated in our database — see source]
    • +2 more quotes in Studies
  • HumanRelative bioavailability and pharmacokinetic comparison of calcium glucoheptonate with calcium carbonate.
    Pharmacol Res Perspect, 2020 · [PMID 32302064]
    • Key findings · abstract:The objective of this study was to compare the relative oral bioavailability of calcium from calcium glucoheptonate, a highly soluble calcium salt containing 8.2% of elemental calcium, to that of calcium carbonate.
    • Key findings · abstract:The relative oral bioavailability of calcium from calcium glucoheptonate as compared to calcium carbonate was 92% within 6 hours and 89% within 12 hours after study drug administration.
    • Key findings · abstract:The 90% confidence intervals for the mean test/reference ratios of the maximum plasma concentration and the area under the concentration-time curve at 12 hours post-administration were 77.09%-120[excerpt truncated in our database — see source]
    • +5 more quotes in Studies
  • HumanEffect of various calcium salts on non-heme iron bioavailability in fasted women of childbearing age.
    J Trace Elem Med Biol, 2018 · n 27 women · [PMID 29895376]
    • Key findings · abstract:Iron was labeled with the radioisotopes 59Fe or 55Fe, and the absorption of iron was measured by erythrocyte incorporation of radioactive Fe RESULTS: 800 mg of elemental calcium as calcium citrate produced a significant decrease in non-heme iron bioavailability (repeated measures ANOVA, F = 3.79, p = 0.018).
  • HumanDietary calcium impairs tomato lycopene bioavailability in healthy humans.
    Br J Nutr, 2016 · [PMID 28069089]
    • Key findings · abstract:Plasma LYC concentration was measured at regular time intervals over 7 h postprandially.
    • Key findings · abstract:LYC bioavailability was diminished by 83 % following the addition of Ca in the test meal.
    • Food effect · abstract:First, in a randomised, two-way cross-over study, ten healthy adults consumed either a test meal that provided 19-mg (all-E)-LYC from tomato paste or the same meal plus 500-mg calcium carbonate as a supplement.
    • +8 more quotes in Studies
  • HumanCalcium carbonate does not affect imatinib pharmacokinetics in healthy volunteers.
    Cancer Chemother Pharmacol, 2014 · [PMID 24170263]
    • Key findings · abstract:Plasma concentrations of imatinib and its active N-desmethyl metabolite CGP74588 were assayed by LC-MS; data were analyzed non-compartmentally and compared after log transformation.
    • Key findings · abstract:RESULTS: Calcium carbonate administration did not significantly affect the imatinib area under the plasma concentration versus time curve (AUC) (41.2 μg/mL h alone vs. 40.8 μg/mL h with calcium carbonate, P = 0.99), maximum plasma concentration (C(max)) (2.35 μg/mL alone vs. 2.39 μg/mL with calcium carbonate, P = 0.89).
    • Cmax · abstract:RESULTS: Calcium carbonate administration did not significantly affect the imatinib area under the plasma concentration versus time curve (AUC) (41.2 μg/mL h alone vs. 40.8 μg/mL h with calcium carbonate, P = 0.99), maximum plasma concentration (C(max)) (2.35 μg/mL alone vs. 2.39 μg/mL with calcium carbonate, P = 0.89).
    • +1 more quotes in Studies
  • HumanA comparative study of calcium absorption following a single serving administration of calcium carbonate powder versus calcium citrate tablets in healthy premenopausal women.
    Food Nutr Res, 2014 · [PMID 24772062]
    • Key findings · abstract:DESIGN: A two-period, crossover bioavailability study of a single serving of calcium citrate tablets (two tablets=500 mg calcium) versus a single serving of calcium carbonate powder (one packet of powder=1,000 mg calcium) was performed in healthy women aged between 25 and 45.
    • Key findings · abstract:Results showed that administration of a single serving of a calcium carbonate powder resulted in greater absorption in total and ionized calcium versus a single serving of calcium citrate tablets at 4 h (4.25±0.21 vs. 4.16±0.16, p=0.001).
    • Food effect · abstract:All subjects were on a calcium-restricted diet 7 days prior to testing and fasted for 12 h before being evaluated at 0, 1, 2, and 4 h after oral administration of the test agents.
    • +3 more quotes in Studies
  • HumanSuperior calcium bioavailability of effervescent potassium calcium citrate over tablet formulation of calcium citrate after Roux-en-Y gastric bypass.
    Surg Obes Relat Dis, 2013 · n 15 patients · [PMID 22222299]
    • Key findings · abstract:To test the hypothesis that effervescent (liquid) potassium-calcium-citrate (PCC) might be more bioavailable than a tablet formulation of calcium citrate (Citracal Petite), the present study compared a single dose response of the 2 compounds.
    • Key findings · abstract:METHODS: A total of 15 patients who had undergone Roux-en-Y gastric bypass were included in a 2-phase, crossover, randomized study comparing the single-dose bioavailability of PCC versus Citracal Petite.
    • Key findings · abstract:Sequential serum and urine samples were collected for a 6-hour period after the dose and analyzed for calcium, parathyroid hormone, and acid-base par[excerpt truncated in our database — see source]
    • +1 more quotes in Studies
  • HumanCalcium carbonate does not affect nilotinib pharmacokinetics in healthy volunteers.
    Cancer Chemother Pharmacol, 2013 · [PMID 24036846]
    • Key findings · abstract:Calcium supplementation did not significantly affect nilotinib pharmacokinetic parameters including area under the plasma concentration versus time curve (18.4 μg/mL h alone vs. 16.9 μg/mL h with calcium carbonate, p = 0.83; 80 % power); maximum plasma concentration (C(max)) (0.670 μg/mL alone vs. 6.18 μg/mL with calcium carbonate, p = 0.97); or half-life (18.9 h alone vs. 17.2 h with calcium carbonate, p = 0.18).
    • Cmax · abstract:Calcium supplementation did not significantly affect nilotinib pharmacokinetic parameters including area under the plasma concentration versus time curve (18.4 μg/mL h alone vs. 16.9 μg/mL h with calcium carbonate, p = 0.83; 80 % power); maximum plasma concentration (C(max)) (0.670 μg/mL alone vs. 6.18 μg/mL with calcium carbonate, p = 0.97); or half-life (18.9 h alone vs. 17.2 h with calcium carbonate, p = 0.18).
    • AUC · abstract:Calcium supplementation did not significantly affect nilotinib pharmacokinetic parameters including area under the plasma concentration versus time curve (18.4 μg/mL h alone vs. 16.9 μg/mL h with calcium carbonate, p = 0.83; 80 % power); maximum plasma concentration (C(max)) (0.670 μg/mL alone vs. 6.18 μg/mL with calcium carbonate, p = 0.97); or half-life (18.9 h alone vs. 17.2 h with calcium carbonate, p = 0.18).
  • HumanCalcium absorption response to cholecalciferol supplementation in hemodialysis.
    Clin J Am Soc Nephrol, 2013 · n 30 participants · [PMID 23411428]
    • Key findings · abstract:DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Paired calcium absorption tests were done before and after 12-13 weeks of 20,000 IU weekly cholecalciferol supplementation in 30 participants with stage 5 CKD on hemodialysis.
    • Key findings · abstract:Calcium absorption was tested with a standardized meal containing 300 mg calcium carbonate intrinsically labeled with (45)Ca; 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were measured.
    • Key findings · abstract:The median baseline calcium absorption was 12% (7%-17%) and 12% (7%-16%) at the end of study.
    • +2 more quotes in Studies
  • HumanPharmacokinetics and pharmacodynamics of calcium-vitamin D(3) chewable tablets: a single-blind, multiple-dose study in postmenopausal women.
    Expert Opin Drug Metab Toxicol, 2011 · [PMID 21635154]
    • Key findings · abstract:OBJECTIVE: The objective of this study is to investigate the effect of a newly developed calcium carbonate-vitamin D₃ chewable tablet formulation (600 mg of calcium + 400 IU of vitamin D₃) on serum/urine calcium and serum parathyroid hormone (PTH) as measures of intestinal calcium absorption compared to a placebo.
    • Key findings · abstract:Total urinary calcium excretion (Ae(0-24 h)) and AUC(0-6 h) for serum calcium were the primary outcome variables and were compared between treatments using a paired sample t-test.
    • Key findings · abstract:RESULTS: Ae(0-24 h) increased by 42% (uncorrected, p = 0.0001) and 30% (creatinine-corrected, p = 0.
    • +4 more quotes in Studies
  • HumanComparison of the absorption of calcium carbonate and calcium citrate after Roux-en-Y gastric bypass.
    Obes Surg, 2009 · [PMID 19437082]
    • Key findings · abstract:Calcium citrate resulted in a significantly higher serum C (max) (9.4 + 0.4 mg/dl vs. 9.2 + 0.3 mg/dl, p = 0.02) and serum AUC (55 + 2 mg/dl vs. 54 + 2 mg/dl, p = 0.02).
    • Key findings · abstract:Calcium citrate resulted in a significantly lower PTH(min) (24 + 11 pg/ml vs. 30 + 13 pg/ml, p = 0.01) and a higher AUC (-32 + 51 pg/ml vs. -3 + 56 pg/ml, p = 0.04).
    • Key findings · abstract:There was a non-significant trend for higher urinary AUC in the calcium citrate group (76.13 + 36.39 mg/6 h vs. 66.04 + 40.82, p = 0.17).
    • +4 more quotes in Studies
  • HumanCalcium retention in adolescent boys on a range of controlled calcium intakes.
    Am J Clin Nutr, 2006 · [PMID 16895892]
    • Key findings · abstract:After a 1-wk equilibration period, calcium retention was calculated as dietary calcium intake minus the calcium excreted in the feces and urine over the following 2 wk.
    • Key findings · abstract:RESULTS: Maximal calcium retention in boys was achieved at an intake of 1140 mg/d.
    • Key findings · abstract:Calcium retention was higher (by 171 +/- 38 mg/d) in boys than in girls at all calcium intakes studied.
  • HumanRelative bioavailability of calcium from calcium formate, calcium citrate, and calcium carbonate.
    J Pharmacol Exp Ther, 2005 · [PMID 15734899]
    • Key findings · abstract:After calcium carbonate, the maximum rise in serum calcium ( approximately 4%) and the fall in serum intact parathyroid hormone 1-84 (iPTH) (approximately 20-40%) did not differ significantly from placebo.
    • Key findings · abstract:After calcium citrate, the changes were modestly but significantly (p < 0.05) greater, but only at 135 to 270 min after ingestion.
    • Key findings · abstract:In contrast, within 60 min after calcium formate serum calcium rose by approximately 15% and serum iPTH fell by 70%.
    • +3 more quotes in Studies
  • HumanCalcium bioavailability of calcium carbonate fortified soymilk is equivalent to cow's milk in young women.
    J Nutr, 2005 · n 20 volunteers · [PMID 16177199]
    • Key findings · abstract:Fractional Ca absorption was determined from the ratios of 43Ca:42Ca and 44Ca:42Ca by inductively coupled plasma (ICP)-MS in the 24-h urine samples.
    • Key findings · abstract:Fractional Ca absorption in CCSM (0.211 +/- 0.057) did not differ from that of cow's milk (0.217 +/- 0.040), but both were higher (P < 0.05) than that of TCPSM (0.181 +/- 0.039).
  • HumanCalcium fortification systems differ in bioavailability.
    J Am Diet Assoc, 2005 · [PMID 15883561]
    • Key findings · abstract:The main outcome measure was the area under the curve (AUC) for the increase in serum calcium from 0 to 9 hours after ingesting the test calcium source.
    • Key findings · abstract:AUC 9 was 48% greater for calcium citrate malate than for tricalcium phosphate/calcium lactate ( P < .001); absorbed calcium calculated from AUC 9 values (mean+/-standard error of the mean) was 148+/-9.0 mg and 100+/-8.9 mg for calcium citrate malate and tricalcium phosphate/calcium lactate, respectively.
    • AUC · abstract:The main outcome measure was the area under the curve (AUC) for the increase in serum calcium from 0 to 9 hours after ingesting the test calcium source.
    • +3 more quotes in Studies
  • HumanEffects of sevelamer hydrochloride and calcium acetate on the oral bioavailability of ciprofloxacin.
    Am J Kidney Dis, 2003 · [PMID 14655198]
    • Key findings · abstract:The authors conducted a 3-way, randomized, crossover study to determine the effects of sevelamer hydrochloride and calcium acetate on the relative oral bioavailability of ciprofloxacin.
    • Key findings · abstract:Pharmacokinetic data were analyzed using noncompartmental methods, and maximum serum concentration (Cmax) and area under the serum concentration time curve from 0 to infinity (AUC(0- infinity )) were tested for bioequivalence after log transformation of the data.
    • Key findings · abstract:The relative oral bioavailability of ciprofloxacin was calculated as AUC(0- infinity ), Arm B or Arm C/AUC(0- infinity ), Arm A.
    • +6 more quotes in Studies
  • HumanMetabolism of the calcium and bioavailability of the salts of most frequent use.
    Boll Chim Farm, 2003 · [PMID 12680036]
    • HumanRelative bioavailability of calcium-rich dietary sources in the elderly.
      Am J Clin Nutr, 2002 · n 9 women · [PMID 12450902]
      • Key findings · abstract:OBJECTIVE: We determined the bioavailability of calcium from 3 different sources: orange juice fortified with calcium-citrate malate, skim milk, and a calcium carbonate supplement.
      • Key findings · abstract:This finding suggests that the calcium bioavailability from the 3 sources was equivalent.
      • Key findings · abstract:During the 1-wk high-calcium diet periods, fasting serum calcium increased by 3% (P < 0.0001), serum 1,25-dihydroxyvitamin D decreased by 20% (P < 0.0001), and a biomarker of bone resorption (serum N-telopeptide collagen cross-links) decreased by 14% (P < 0.02) compared with the low-calcium diet period.
      • +4 more quotes in Studies
    • HumanCalcium absorption from three salts and CaSO(4)-fortified bread in premenopausal women.
      J Agric Food Chem, 2002 · [PMID 12059174]
      • Key findings · abstract:In study I, calcium fractional absorption levels from the three salts labeled with a stable isotope, 44Ca, were not significantly different (0.039-0.47) as determined by the fecal recovery method.
      • Key findings · abstract:In a second study, absorption of 45Ca from CaSO(4)-fortified labeled bread or labeled milk was measured in serum exactly 5 h postingestion.
      • Key findings · abstract:Fractional calcium absorption was slightly but significantly greater from fortified bread than from milk (mean within subject difference = 0.0675 +/- 0.016).
      • +1 more quotes in Studies
    • HumanEffect of estrogen treatment and vitamin D status on differing bioavailabilities of calcium carbonate and calcium citrate.
      J Clin Pharmacol, 2002 · [PMID 12412824]
      • Key findings · abstract:Using data derived from a recent trial in 25 postmenopausal women, the authors found that deltaAUC of serum calcium after subtraction of placebo was significantly higher after calcium citrate (median, 0.85; 25th to 75th percentile, 0.70 to 3.15) than after calcium carbonate (0.25; -0.58 to 1.00) in non-estrogen-treated patients.
      • Key findings · abstract:Bioavailability was also significantly higher with the citrate salt for the subgroups with lower serum 25-hydroxyvitamin D and higher serum 1,25-dihydroxyvitamin D concentrations.
    • HumanHigh bioavailability of calcium in fortified Horlicks.
      Eur J Clin Nutr, 2001 · [PMID 11528493]
      • Key findings · abstract:RESULTS: Mean true fractional calcium absorption was 38.8% (s.d.+/-14.5) from Horlicks and 21.2% (s.d.+/-4.6) from milk.
      • Key findings · abstract:Significantly more calcium was absorbed from a serving of Horlicks than from the same quantity of calcium present in 420 g semi-skimmed milk (P<0.001).
      • Fractional absorption · abstract:Significantly more calcium was absorbed from a serving of Horlicks than from the same quantity of calcium present in 420 g semi-skimmed milk (P<0.001).
    • HumanAbsorbability and cost effectiveness in calcium supplementation.
      J Am Coll Nutr, 2001 · [PMID 11444420]
      • Key findings · abstract:SUBJECTS: 24 postmenopausal women METHODS: Pharmacokinetic analysis of the increment in serum total and ionized calcium and the decrement in serum iPTH induced by an oral calcium load, based upon multiple blood samples over a 24-hour period; measurement of the rise in urine calcium excretion.
      • Key findings · abstract:RESULTS: All three calcium sources (marketed calcium carbonate, encapsulated calcium carbonate and marketed calcium citrate) produced identical 24-hour time courses for the increment in total serum calcium.
    • HumanAcute biochemical variations induced by calcium citrate and calcium carbonate in Type 2 diabetic patients: impaired calcium absorption in Type 2 diabetic patients with prolonged gastric emptying time.
      J Diabetes Complications, 2001 · [PMID 11274906]
      • Key findings · abstract:Serum free calcium, intact parathyroid hormone (i-PTH), and amount of urinary excretion of calcium (uCal/uCr) were evaluated after a single dose of 1200 mg of elemental calcium in each preparation.
      • Key findings · abstract:After administration of calcium citrate, the uCal/uCr of 2-to-4-h collection was significantly higher than that of the basal and 0-to-2-h collections: 0.25+/-0.04 vs. 0.19+/-0.03, P=.025; and 0.25+/-0.04 vs. 0.19+/-0.02, P=.014, respectively.
    • HumanCarbonated beverages and urinary calcium excretion.
      Am J Clin Nutr, 2001 · [PMID 11522558]
      • Key findings · abstract:RESULTS: Relative to water, urinary calcium rose significantly only with the milks and the 2 caffeine-containing beverages.
      • Food effect · abstract:Beverages were consumed with a light breakfast after an overnight fast; no other foods were ingested until urine collection was complete. pH, titratable and total acidity, sodium, creatinine, and calcium were measured in 2-h (morning) fasting and 5-h postbeverage urine specimens.
    • HumanPharmacokinetic and pharmacodynamic comparison of two calcium supplements in postmenopausal women.
      J Clin Pharmacol, 2000 · [PMID 11075309]
      • Key findings · abstract:This randomized crossover study compared the single-dose bioavailability and effects on parathyroid function of two commercially formulated calcium supplements containing 500 mg of elemental calcium.
      • Key findings · abstract:Compared with calcium carbonate, calcium citrate provided a 46% greater peak-basal variation and 94% higher change in area under the curve for serum calcium and a 41% greater increment in urinary calcium.
      • AUC · abstract:Compared with calcium carbonate, calcium citrate provided a 46% greater peak-basal variation and 94% higher change in area under the curve for serum calcium and a 41% greater increment in urinary calcium.
      • +1 more quotes in Studies
    • HumanPharmacokinetics of calcium absorption from two commercial calcium supplements.
      J Clin Pharmacol, 1999 · [PMID 10579145]
      • Key findings · abstract:This study was conducted to compare pharmacokinetic indices of calcium absorption after a single oral (500 mg calcium) load of Citracal (calcium citrate) and Os-Cal (calcium carbonate).
      • Key findings · abstract:The change in area under the curve (delta AUC) in serum calcium from preload was 2.5-fold greater for Citracal than Os-Cal, and the peak-basal variation in serum calcium was 76% higher for Citracal than Os-Cal.
      • Key findings · abstract:The increment in serum calcium from preload after Citracal administration was significantly higher than that obtained after placebo load during most time periods and significantly higher than that of[excerpt truncated in our database — see source]
      • +4 more quotes in Studies
    • HumanCalcium bioavailability and parathyroid hormone acute changes after oral intake of dairy and nondairy products in healthy volunteers.
      Osteoporos Int, 1999 · [PMID 10501794]
      • Key findings · abstract:This study was designed to compare calcium bioavailability and serum parathyroid hormone acute changes after oral intake of 500 mg of elemental calcium from liquid milk, yogurt, calcium-citrate-enriched powdered milk or a calcium carbonate pill; or after intake of soybean imitation-milk.
      • Key findings · abstract:Calcium-citrate-enriched powdered milk induced a significant increase in serum ionized calcium (p<0.001) and a significant and continuous decrease in serum iPTH concentration (p<0. 001).
      • Key findings · abstract:Yogurt and the calcium carbonate pill induced a similar but less significant effect, increasing serum ionized calcium (p[excerpt truncated in our database — see source]
      • +1 more quotes in Studies
    • HumanComparative study of the intestinal absorption of three salts of calcium in young and elderly women.
      J Endocrinol Invest, 1998 · n n = 7 · [PMID 9624602]
      • Key findings · abstract:We have compared the digestive absorption of calcium (Ca) citrate in soluble and solid form and calcium gluconolactate-carbonate in 15 young and 20 elderly, healthy women using the oral calcium loading test.
      • Key findings · abstract:In the first group, the absorption of solid Ca citrate (1000 mg Ca element) was compared to the absorption of Ca gluconolactate-carbonate (1000 mg Ca element) both in young (n = 7) and elderly women (n = 10).
      • Key findings · abstract:In the second group, the absorption of soluble Ca citrate (1000 mg Ca element) was compared to the absorption of Ca gluconolactate-carbonate (1000 mg Ca element) in young (n = 8)
    • HumanEffect of dietary calcium on urinary oxalate excretion after oxalate loads.
      Am J Clin Nutr, 1997 · [PMID 9129476]
      • Key findings · abstract:Mean 24-h oxalate absorption decreased significantly from that at the time of the baseline treatment (18.3%) after both calcium carbonate (8.1%) and CCM (7.2%) treatments.
      • Key findings · abstract:In R-2, mean 24-h oxalate absorption was significantly lower after 200 (5.9%) and 300 (7.6%) mg Ca than after 100 mg Ca (9.1%) and the OL alone (11.3%).
      • Key findings · abstract:Concomitant meal ingestion significantly decreased oxalate absorption in the absence of dietary calcium but not in association with the 300-mg Ca treatment.
      • +1 more quotes in Studies
    • HumanCalcium retention in relation to calcium intake and postmenarcheal age in adolescent females.
      Am J Clin Nutr, 1997 · n 14 subjects · [PMID 9250111]
      • Key findings · abstract:Mean maximal calcium retention was 473 mg/d (95% CI: 245, 701 mg Ca/d).
      • Key findings · abstract:Calcium intake explained 79% and 6%, respectively, of the variation in fecal and urinary calcium excretion.
      • Key findings · abstract:Intake of 1200 mg Ca/d, the recommended dietary allowance for calcium published in 1989, resulted in a mean calcium retention that was 57% of the maximal value (95% CI: 25%, 89%).
      • +2 more quotes in Studies
    • HumanPostprandial parathyroid hormone response to four calcium-rich foodstuffs.
      Am J Clin Nutr, 1997 · [PMID 9174467]
      • Key findings · abstract:The serum ionized calcium concentration increased significantly after ingesting cheese (P = 0.004, contrast analysis) or calcium salt (P = 0.05, contrast analysis) compared with the control session.
      • Key findings · abstract:Compared with the control session, the serum phosphate concentration increased after the cheese session (P = 0.004, contrast analysis) and after the milk session (P = 0.02, contrast analysis).
      • Key findings · abstract:Calcium salt (P = 0.007, contrast analysis) and cheese (P = 0.002, contrast analysis) caused a significant decline in serum intact parathyroid hormone compared with the control session.
      • +2 more quotes in Studies
    • HumanIntestinal calcium absorption from different calcium preparations: influence of anion and solubility.
      Osteoporos Int, 1996 · n 18 healthy volunteers · [PMID 8931033]
      • Key findings · abstract:In the present study, the bioavailability of calcium citrate and calcium lactogluconate/carbonate from a therapeutic dose (= 500 mg Ca2+) was compared in men aged between 45 and 60 years on an intra-individual basis.
      • Key findings · abstract:Using a double-isotope method, the intestinal absorption from the three preparations was determined in randomized order at intervals of 2-4 weeks.
      • Key findings · abstract:The intestinal calcium absorption was then determined after 24 h on the basis of the ratio of the two isotopes in the plasma.
      • +1 more quotes in Studies
    • HumanBioavailability of calcium supplements and the effect of Vitamin D: comparisons between milk, calcium carbonate, and calcium carbonate plus vitamin D.
      Am J Clin Nutr, 1996 · n 20 healthy women · [PMID 8602592]
      • Key findings · abstract:Bioavailability of the different calcium-supplement regimens were evaluated by changes in 24-h urinary excretion of calcium, phosphate, and magnesium.
      • Key findings · abstract:A significant increase in urinary calcium excretion was found during all periods of supplementation compared with the placebo period (P<0.01).
      • Key findings · abstract:We conclude that the examined calcium carbonate regimen is at least as good a calcium supplement as milk, and that addition of 600 IU vitamin D/d promptly resulted in an increase in urinary calcium excretion after an increase in calcium absorption, even in healthy women.
    • HumanComparison of serum calcium levels between junior high school children with high-normal and low-normal blood pressure. The child and adolescent blood pressure program.
      Am J Hypertens, 1994 · n 243 children · [PMID 7702797]
      • Key findings · abstract:Calcium measurements were based on the principle that serum calcium is found in three forms: 1) an ionized fraction; 2) a fraction complexed with organic anions such as citrate, phosphate, and lactate; and 3) a protein-bound fraction.
      • Key findings · abstract:Dietary calcium intake was determined from food diaries, and urinary electrolytes were determined in 24-h urine collections.
      • Key findings · abstract:This report of the relation between calcium and blood pressure represents the first study in children or adolescents to include serum, dietary, and urine data.(ABSTRACT TRUNCATED AT 250 WORDS)
    • HumanEffect of added citrate or malate on calcium absorption from calcium-fortified orange juice.
      J Am Coll Nutr, 1994 · [PMID 7706589]
      • Key findings · abstract:OBJECTIVE: Calcium absorption was determined from calcium-fortified diluted orange juice, which contained additional citrate or malate, in 16 normal subjects.
      • Key findings · abstract:For each subject, fractional (intestinal) calcium absorption was measured by taking the ratio of fractional forearm radioactivity following an oral administration of OJ+C or OJ+M (labeled with 47Ca) and the fractional forearm radioactivity obtained after intravenous administration of trace 47Ca chloride on a separate occasion.
      • Key findings · abstract:RESULTS: There was no significant difference in fractional calcium absorption from the two calcium-fortified[excerpt truncated in our database — see source]
    • HumanShort-term dietary calcium fortification increases fecal saturated fat content and reduces serum lipids in men.
      J Nutr, 1993 · n 13 healthy men · [PMID 8505664]
      • Key findings · abstract:The effect of dietary calcium on fecal fatty acid excretion and serum lipids was tested in a randomized, single-blind metabolic study in 13 healthy men with moderate hypercholesterolemia.
      • Key findings · abstract:The percentage of dietary saturated fat excreted per day increased from 6 to 13% with calcium fortification.
      • Key findings · abstract:Urinary calcium excretion increased from 146 to 230 mg/d when the high Ca diet was consumed.
      • +1 more quotes in Studies
    • HumanFluoride bioavailability from immediate-release sodium fluoride with calcium carbonate compared with slow-release sodium fluoride with calcium citrate.
      Bone Miner, 1991 · [PMID 1912761]
      • Key findings · abstract:The circadian variation in serum fluoride was compared between treatment with immediate-release sodium fluoride (IR-NaF) (30 mg) and calcium carbonate (500 mg calcium) and slow-release sodium fluoride (SR-NaF) (25 mg) and calcium citrate (400 mg calcium) in seven patients with postmenopausal osteoporosis maintained on long-term fluoride treatment.
      • Key findings · abstract:During 12 h following a dose of SR-NaF, serum fluoride levels could be largely kept within the therapeutic window (believed to be 95-190 ng/ml or 5-10 mumol/l).
      • Key findings · abstract:Compared to SR-NaF, IR-NaF caused a significantly higher peak fluoride concentration[excerpt truncated in our database — see source]
      • +1 more quotes in Studies
    • HumanCalcium bioavailability from calcium fortified food products.
      J Nutr Sci Vitaminol (Tokyo), 1991 · [PMID 1765836]
      • Food effect · full text, p.4:um-fortified food products under study (orange juice OJ, milk M, soda S, and experimental cheese T) or a calcium carbonate plus vitamin D tablet (CC) with breakfast. The calcium sources used to fortify these food products were different. For example: S contained CaCO3+Ca gluconate , T contained Ca3PO4, OJ contained Ca citrate malate and the milk contained CaCO3. Supplemented calcium in experimenta
      • Food effect · full text, p.9:um salts. N. Engl. J. Med., 317, 532-536. 13) Greger, J. L., Krzykowski, C. E., Khazen, R. R., and Krashol, C. L. (1987): Mineral utilization by rats fed various commercially available calcium supplements or milk. J. Nutr., 117, 717-724. 14) Recker, R. R., Bammi, A., Barger-Lux, M. J., and Heaney, P. R. (1988): Calcium absorbability from milk products, an imitation milk and calcium carbonate. Am.
      • Form comparison · full text, p.4:um excretions were not found to be statistically significantly different, but fecal calcium tended to be lower when subjects consumed M, OJ, and S as compared to control, CC, and T (39 .4. 550, and 43.2% versus 50.1, 54.4, and 55.5%, respectively) . A few recently-published studies reported that the form of calcium in the orange juice used in this experiment J. Nutr, Sci. Vitaminol.
      • +2 more quotes in Studies
    • HumanCalcium supplementation: effect on iron absorption.
      Am J Clin Nutr, 1991 · [PMID 1984334]
      • Key findings · abstract:The influence of calcium supplements on the absorption of dietary nonheme iron and of iron supplements was evaluated in 61 normal volunteer subjects by use of a double-radioisotope technique.
      • Key findings · abstract:When taken without food, calcium carbonate did not inhibit the absorption of ferrous sulphate with doses of either 300 mg Ca and 37 mg Fe or 600 mg Ca and 18 mg Fe.
      • Key findings · abstract:However, at the latter levels, calcium citrate and calcium phosphate reduced iron absorption significantly by 49% and 62%, respectively.
      • +1 more quotes in Studies
    • HumanCalcium citrate markedly enhances aluminum absorption from aluminum hydroxide.
      Am J Kidney Dis, 1991 · [PMID 2042654]
      • Key findings · abstract:Baseline urinary aluminum excretion was determined for 2 days; thereafter, subjects ingested aluminum hydroxide for 3 days.
      • Key findings · abstract:Baseline urinary aluminum excretion was 0.02 +/- 0.004 (6.5 +/- 1.1 micrograms/g creatinine) and 0.03 +/- 0.005 mumol/mmol creatinine (7.4 +/- 1.3 micrograms/g creatinine).
      • Key findings · abstract:On 3 consecutive days, urinary aluminum excretion levels were 11.1 +/- 3.23, 8.8 +/- 2.9, and 5.3 +/- 0.7 times greater during the administration of calcium citrate with aluminum hydroxide than with aluminum hydroxide alone.
    • Human[Combined administration of calcium and citrate reduces urinary oxalate excretion].
      Hinyokika Kiyo, 1991 · [PMID 1755399]
      • HumanFluoride bioavailability from slow-release sodium fluoride given with calcium citrate.
        J Bone Miner Res, 1990 · [PMID 2239370]
        • Key findings · abstract:Following a single oral administration of 50 mg slow-release sodium fluoride, a peak serum fluoride concentration (Cmax) of 184 ng/ml was reached in 2 h; thereafter, serum fluoride concentration declined with a T1/2 of 5.9 h.
        • Key findings · abstract:The concurrent administration of calcium citrate (400 mg calcium) gave an equivalent Tmax (time required to attain Cmax) and T1/2, but a lower Cmax of 135 ng/ml.
        • Key findings · abstract:The area under the serum concentration curve of slow-release sodium fluoride was reduced 17-27% by a meal or calcium citrate.
        • +6 more quotes in Studies
      • HumanEffects of different calcium sources on iron absorption in postmenopausal women.
        Am J Clin Nutr, 1990 · [PMID 2296934]
        • Key findings · abstract:We measured the effect of calcium from food and supplement sources on whole-body retention of 59Fe in 19 normal postmenopausal women.
        • Key findings · abstract:Retention of 59Fe was 8.3 +/- 1.1% (means +/- SEM) with placebo, 3.4 +/- 0.78% with milk, 6.0 +/- 0.97% with CCM, and 7.4 +/- 1.7% with CCM plus orange juice.
        • Key findings · abstract:When compared with placebo, milk and CCM significantly lowered iron retention (p less than 0.05) whereas CCM plus orange juice did not.
        • +5 more quotes in Studies
      • HumanSuperior calcium absorption from calcium citrate than calcium carbonate using external forearm counting.
        J Am Coll Nutr, 1990 · [PMID 2273192]
        • Key findings · abstract:Calcium absorption from calcium citrate was compared with that obtained from calcium carbonate in 20 normal women.
        • Key findings · abstract:It was measured by external forearm counting technique, where the ratio of forearm radioactivity after an oral dose of labeled calcium salt (containing 500 mg calcium) and after an intravenous injection of trace radiocalcium represented fractional calcium absorption.
        • Key findings · abstract:The fractional calcium absorption from calcium citrate was 39.2 +/- 8.6%, which was significantly higher than the 31.2 +/- 9.4% derived from calcium carbonate (p less than 0.001).
      • HumanCalcium supplementation lowers serum parathyroid hormone levels in elderly subjects.
        J Gerontol, 1990 · n 40 healthy volunteers · [PMID 2203847]
        • Key findings · abstract:Calcium supplementation (1000 mg/day) decreased serum PTH levels from a mean of 50.1 +/- 3.0 pg/ml to 41.9 +/- 2.4 pg/ml (p less than .001).
        • Key findings · abstract:Additionally, urine calcium excretion significantly increased during calcium administration (from 3.64 mmol/mmol creatinine at baseline to 4.28 mmol/mmol creatinine), but creatinine clearances and serum calcium levels remained unchanged.
        • Food effect · abstract:Fasting blood samples and 24-hour urine collections were obtained at baseline, and at the end of each intervention period.
      • HumanCalcium absorption in children estimated from single and double stable calcium isotope techniques.
        Clin Chim Acta, 1989 · [PMID 2791301]
        • Key findings · abstract:High-resolution, fast atom bombardment mass spectrometry was used to quantify the 44Ca and 42Ca tracers in serum and urine.
        • Key findings · abstract:The average calcium absorption estimated from the ratio of urinary tracers was 41.4 +/- 8.2%.
        • Key findings · abstract:This study indicates that the level of oral tracer in serum taken 150 min post-ingestion is significantly correlated (r = 0.85, p less than 0.05) with calcium absorption, as determined by the tracer levels in the urine.
        • +1 more quotes in Studies
      • HumanDose dependency of calcium absorption: a comparison of calcium carbonate and calcium citrate.
        J Bone Miner Res, 1988 · n 4 men · [PMID 3213620]
        • Key findings · abstract:Using the well-described oral calcium load technique, we measured the calcium absorption from three different calcium doses (0.5, 1.0, and 2.0 g) of both calcium carbonate and calcium citrate administered to 21 normal subjects (4 men and 17 women, 22-60 years).
        • Key findings · abstract:The increment in urinary calcium post-load, reflective of intestinal calcium absorption, rose rapidly from 0 to 0.5 g calcium loads with only slight subsequent increases from the 0.5 g to 2.0 g calcium doses.
        • Key findings · abstract:The increment in urinary calcium (during the second 2 hr) following calcium citrate load (0.5 g calcium) was 0.104 +/- 0.096[excerpt truncated in our database — see source]
      • HumanCalcium absorption from calcium carbonate and a new form of calcium (CCM) in healthy male and female adolescents.
        Am J Clin Nutr, 1988 · [PMID 3189218]
        • Key findings · abstract:Calcium absorption from two Ca salts was investigated in a crossover design using stable isotopic tracers in 12 healthy adolescents (6 males, 6 females).
        • Key findings · abstract:The molar concentrations of 42Ca and 44Ca tracers in a urine sample obtained 24 h after tracer administration were quantified by fast-atom-bombardment mass spectrometry and used to determine fractional absorption of the Ca from the supplement.
        • Key findings · abstract:Ca in the form of CCM had an increased fractional absorption (p less than 0.03) relative to Ca carbonate in healthy adolescents (36.2 vs 26.4%).
        • +2 more quotes in Studies
      • HumanCalcium absorption: effect of meal and glucose polymer.
        Am J Clin Nutr, 1988 · [PMID 3407610]
        • Key findings · abstract:Using a single-day method, we measured net Ca absorption from Ca carbonate when ingested in fasting state, with a steak and potatoes meal, and with the meal and 50 g glucose polymer.
        • Key findings · abstract:Mean net Ca absorption was 195 +/- 18 mg (4.87 +/- 0.45 mmol) fasting, 213 +/- 21 mg (5.31 +/- 0.52 mmol) with a meal, and 179 +/- 16 mg (4.47 +/- 0.40 mmol) with a meal plus glucose polymer.
        • Key findings · abstract:In normal people Ca absorption from Ca carbonate was not significantly enhanced by a meal or by 50 g glucose polymer ingested with food.
        • +3 more quotes in Studies
      • HumanEnhanced calcium bioavailability from a solubilized form of calcium citrate.
        J Clin Endocrinol Metab, 1987 · [PMID 3654922]
        • Key findings · abstract:Intestinal calcium absorption, measured from the increment in urinary calcium during the second 2 h following an oral calcium load (500 mg) in 15 normal subjects was significantly higher from the mixtures (calcium to citrate molar ratios of 1.5 and 1.25) than from tricalcium dicitrate.
        • Key findings · abstract:The fractional calcium absorption, obtained from fecal recovery of radiocalcium after oral administration of 500 mg calcium prelabeled with 47Ca in 11 normal subjects, was also higher for the mixture with a calcium to citrate molar ratio of 1.25.
        • Key findings · abstract:The most efficient calcium absorption was obtained with the mi[excerpt truncated in our database — see source]
      • HumanGastrointestinal absorption of calcium from milk and calcium salts.
        N Engl J Med, 1987 · [PMID 3614304]
        • Key findings · abstract:Using a method by which the net absorption of calcium can be accurately measured after a single dose, we studied eight healthy fasting subjects after they took a 500-mg dose of calcium from each of five calcium salts with various degrees of water solubility and from milk.
        • Key findings · abstract:The mean (+/- SEM) net calcium absorption, in decreasing order of the solubility of the salts, was 32 +/- 4 percent from calcium acetate, 32 +/- 4 percent from calcium lactate, 27 +/- 3 percent from calcium gluconate, 30 +/- 3 percent from calcium citrate, and 39 +/- 3 percent from calcium carbonate.
        • Key findings · abstract:Calcium absorption fr[excerpt truncated in our database — see source]
        • +1 more quotes in Studies
      • HumanCalcium bioavailability from calcium carbonate and calcium citrate.
        J Clin Endocrinol Metab, 1985 · [PMID 4008614]
        • Key findings · abstract:The urinary calcium following calcium citrate load significantly higher (by 20-66%), whether expressed as the total amount or as the increment above basal (fasting) excretion.
        • Food effect · abstract:The urinary calcium following calcium citrate load significantly higher (by 20-66%), whether expressed as the total amount or as the increment above basal (fasting) excretion.
      • HumanCalcium absorption and achlorhydria.
        N Engl J Med, 1985 · [PMID 4000241]
        • Key findings · abstract:I compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects.
        • Key findings · abstract:Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier.
        • Key findings · abstract:Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001).
        • +2 more quotes in Studies
      • HumanAn evaluation of the importance of gastric acid secretion in the absorption of dietary calcium.
        J Clin Invest, 1984 · [PMID 6707197]
        • Key findings · abstract:Since calcium solubility is a prerequisite to calcium absorption, and since solubility of calcium is highly pH-dependent, it has been generally assumed that gastric acid secretion and gastric acidity play an important role in the intestinal absorption of calcium from ingested food or calcium salts such as CaCO3.
        • Key findings · abstract:Moreover, calcium absorption after CaCO3 ingestion was the same when intragastric contents were maintained at pH 7.4 (by in vivo titration) as when intragastric pH was 3.0.
      • RodentBone composition and histology of young growing rats fed diets of varied calcium bioavailability: spinach, nonfat dry milk, or calcium carbonate added to casein.
        J Nutr, 1992 · [PMID 1729463]
        • Key findings · abstract:In contrast, when calcium is fed to growing animals at levels below the National Research Council requirement but from a highly bioavailable source (i.e., NFDM and CaCO3), there is only a reduction in bone quantity.
        • Food effect · abstract:Bone composition and histology were evaluated in young growing rats fed nutritionally complete but calcium-restricted (0.15%) diets in which calcium was derived from spinach, nonfat dry milk (NFDM), or CaCO3 added to casein.
        • Food effect · abstract:Groups of male weanling rats were pair-fed for 28 d.
        • +2 more quotes in Studies
      • Other animalSolubility and bioavailability of stabilized amorphous calcium carbonate.
        J Bone Miner Res, 2011 · [PMID 20690187]
        • Key findings · abstract:Since its role in the prevention of osteoporosis in humans was proven some 30 years ago, calcium bioavailability has been the subject of numerous scientific studies.
        • Key findings · abstract:Fractional absorption was evaluated by intrinsically labeling calcium carbonate preparations with (45)Ca, orally administrated to rats using gelatin capsules.
        • Key findings · abstract:Fractional absorption was determined by evaluating the percentage of the administrated radioactive dose per milliliter that was measured in the serum, calcium absorption in the femur, and whole-body retention over a 34-hour period.
        • +4 more quotes in Studies
      • Other animalCalcium absorption from apple and orange juice fortified with calcium citrate malate (CCM).
        J Am Coll Nutr, 1996 · n n = 57 · [PMID 8935449]
        • Key findings · abstract:METHODS: Absorbability was assessed by measuring 45Ca absorption in healthy women (mean age 57 years, n = 57/group) and whole body 47Ca retention in adult female beagle dogs (n = 6/group) and young adult male rats (n = 6/group).
        • Key findings · abstract:Additional 47Ca whole body retention experiments in rats measured the effects of differences in the carbohydrate and organic acid contents of the juices on Ca absorption.
        • Key findings · abstract:RESULTS: Mean +/- SEM percent Ca fractional absorption was greater (p < 0.003) in women who consumed CCM-AJ (42 +/- 2%) than those who consumed CCM-OJ (36 +/- 1%).
        • +1 more quotes in Studies

      Calcium citrate vs carbonate: which absorbs better?

      Citrate measured higher than carbonate in 7 of 12 human head-to-head studies we have (grade C, draft). See the measured values →

      Species (abstract screen): 22 human
      Show 22 studies with verbatim quotes
      • HumanComparison of calcium citrate and calcium carbonate absorption in patients with a Roux-en-Y gastric bypass, sleeve gastrectomy, and one-anastomosis gastric bypass: a double-blind, randomized cross-over trial.
        Surg Obes Relat Dis, 2025 · [PMID 39603923]
        • Key findings · abstract:The intestinal absorption of Ca carbonate and Ca citrate among groups divided by surgical procedure was compared over 8 hours of testing.
        • Key findings · abstract:Measurements included serum and urine Ca concentrations for peak values (Cmax) and area under the curve (AUC0-8h), along with parathyroid hormone (PTH) levels to calculate minimum PTH (PTHmin) and cumulative PTH decline (AUC0-8h).
        • Key findings · abstract:Ca citrate also demonstrated superior relative bioavailability, as evidenced by a higher AUC0-8h of 76.1 mg/dL·h versus 74.7 mg/dL·h for carbonate (P = .001) and a Cmax of 9.8 mg/dL compared to 9.5 mg/dL for carbonate (P < .001[excerpt truncated in our database — see source]
        • +5 more quotes in Studies
      • HumanEffect of various calcium salts on non-heme iron bioavailability in fasted women of childbearing age.
        J Trace Elem Med Biol, 2018 · n 27 women · [PMID 29895376]
        • Key findings · abstract:Iron was labeled with the radioisotopes 59Fe or 55Fe, and the absorption of iron was measured by erythrocyte incorporation of radioactive Fe RESULTS: 800 mg of elemental calcium as calcium citrate produced a significant decrease in non-heme iron bioavailability (repeated measures ANOVA, F = 3.79, p = 0.018).
      • HumanA comparative study of calcium absorption following a single serving administration of calcium carbonate powder versus calcium citrate tablets in healthy premenopausal women.
        Food Nutr Res, 2014 · [PMID 24772062]
        • Key findings · abstract:DESIGN: A two-period, crossover bioavailability study of a single serving of calcium citrate tablets (two tablets=500 mg calcium) versus a single serving of calcium carbonate powder (one packet of powder=1,000 mg calcium) was performed in healthy women aged between 25 and 45.
        • Key findings · abstract:Results showed that administration of a single serving of a calcium carbonate powder resulted in greater absorption in total and ionized calcium versus a single serving of calcium citrate tablets at 4 h (4.25±0.21 vs. 4.16±0.16, p=0.001).
        • Food effect · abstract:All subjects were on a calcium-restricted diet 7 days prior to testing and fasted for 12 h before being evaluated at 0, 1, 2, and 4 h after oral administration of the test agents.
        • +3 more quotes in Studies
      • HumanComparison of the absorption of calcium carbonate and calcium citrate after Roux-en-Y gastric bypass.
        Obes Surg, 2009 · [PMID 19437082]
        • Key findings · abstract:Calcium citrate resulted in a significantly higher serum C (max) (9.4 + 0.4 mg/dl vs. 9.2 + 0.3 mg/dl, p = 0.02) and serum AUC (55 + 2 mg/dl vs. 54 + 2 mg/dl, p = 0.02).
        • Key findings · abstract:Calcium citrate resulted in a significantly lower PTH(min) (24 + 11 pg/ml vs. 30 + 13 pg/ml, p = 0.01) and a higher AUC (-32 + 51 pg/ml vs. -3 + 56 pg/ml, p = 0.04).
        • Key findings · abstract:There was a non-significant trend for higher urinary AUC in the calcium citrate group (76.13 + 36.39 mg/6 h vs. 66.04 + 40.82, p = 0.17).
        • +4 more quotes in Studies
      • HumanRelative bioavailability of calcium from calcium formate, calcium citrate, and calcium carbonate.
        J Pharmacol Exp Ther, 2005 · [PMID 15734899]
        • Key findings · abstract:After calcium carbonate, the maximum rise in serum calcium ( approximately 4%) and the fall in serum intact parathyroid hormone 1-84 (iPTH) (approximately 20-40%) did not differ significantly from placebo.
        • Key findings · abstract:After calcium citrate, the changes were modestly but significantly (p < 0.05) greater, but only at 135 to 270 min after ingestion.
        • Key findings · abstract:In contrast, within 60 min after calcium formate serum calcium rose by approximately 15% and serum iPTH fell by 70%.
        • +3 more quotes in Studies
      • HumanMetabolism of the calcium and bioavailability of the salts of most frequent use.
        Boll Chim Farm, 2003 · [PMID 12680036]
        • HumanEffect of estrogen treatment and vitamin D status on differing bioavailabilities of calcium carbonate and calcium citrate.
          J Clin Pharmacol, 2002 · [PMID 12412824]
          • Key findings · abstract:Using data derived from a recent trial in 25 postmenopausal women, the authors found that deltaAUC of serum calcium after subtraction of placebo was significantly higher after calcium citrate (median, 0.85; 25th to 75th percentile, 0.70 to 3.15) than after calcium carbonate (0.25; -0.58 to 1.00) in non-estrogen-treated patients.
          • Key findings · abstract:Bioavailability was also significantly higher with the citrate salt for the subgroups with lower serum 25-hydroxyvitamin D and higher serum 1,25-dihydroxyvitamin D concentrations.
        • HumanAbsorbability and cost effectiveness in calcium supplementation.
          J Am Coll Nutr, 2001 · [PMID 11444420]
          • Key findings · abstract:SUBJECTS: 24 postmenopausal women METHODS: Pharmacokinetic analysis of the increment in serum total and ionized calcium and the decrement in serum iPTH induced by an oral calcium load, based upon multiple blood samples over a 24-hour period; measurement of the rise in urine calcium excretion.
          • Key findings · abstract:RESULTS: All three calcium sources (marketed calcium carbonate, encapsulated calcium carbonate and marketed calcium citrate) produced identical 24-hour time courses for the increment in total serum calcium.
        • HumanAcute biochemical variations induced by calcium citrate and calcium carbonate in Type 2 diabetic patients: impaired calcium absorption in Type 2 diabetic patients with prolonged gastric emptying time.
          J Diabetes Complications, 2001 · [PMID 11274906]
          • Key findings · abstract:Serum free calcium, intact parathyroid hormone (i-PTH), and amount of urinary excretion of calcium (uCal/uCr) were evaluated after a single dose of 1200 mg of elemental calcium in each preparation.
          • Key findings · abstract:After administration of calcium citrate, the uCal/uCr of 2-to-4-h collection was significantly higher than that of the basal and 0-to-2-h collections: 0.25+/-0.04 vs. 0.19+/-0.03, P=.025; and 0.25+/-0.04 vs. 0.19+/-0.02, P=.014, respectively.
        • HumanPharmacokinetic and pharmacodynamic comparison of two calcium supplements in postmenopausal women.
          J Clin Pharmacol, 2000 · [PMID 11075309]
          • Key findings · abstract:This randomized crossover study compared the single-dose bioavailability and effects on parathyroid function of two commercially formulated calcium supplements containing 500 mg of elemental calcium.
          • Key findings · abstract:Compared with calcium carbonate, calcium citrate provided a 46% greater peak-basal variation and 94% higher change in area under the curve for serum calcium and a 41% greater increment in urinary calcium.
          • AUC · abstract:Compared with calcium carbonate, calcium citrate provided a 46% greater peak-basal variation and 94% higher change in area under the curve for serum calcium and a 41% greater increment in urinary calcium.
          • +1 more quotes in Studies
        • HumanPharmacokinetics of calcium absorption from two commercial calcium supplements.
          J Clin Pharmacol, 1999 · [PMID 10579145]
          • Key findings · abstract:This study was conducted to compare pharmacokinetic indices of calcium absorption after a single oral (500 mg calcium) load of Citracal (calcium citrate) and Os-Cal (calcium carbonate).
          • Key findings · abstract:The change in area under the curve (delta AUC) in serum calcium from preload was 2.5-fold greater for Citracal than Os-Cal, and the peak-basal variation in serum calcium was 76% higher for Citracal than Os-Cal.
          • Key findings · abstract:The increment in serum calcium from preload after Citracal administration was significantly higher than that obtained after placebo load during most time periods and significantly higher than that of[excerpt truncated in our database — see source]
          • +4 more quotes in Studies
        • HumanCalcium bioavailability and parathyroid hormone acute changes after oral intake of dairy and nondairy products in healthy volunteers.
          Osteoporos Int, 1999 · [PMID 10501794]
          • Key findings · abstract:This study was designed to compare calcium bioavailability and serum parathyroid hormone acute changes after oral intake of 500 mg of elemental calcium from liquid milk, yogurt, calcium-citrate-enriched powdered milk or a calcium carbonate pill; or after intake of soybean imitation-milk.
          • Key findings · abstract:Calcium-citrate-enriched powdered milk induced a significant increase in serum ionized calcium (p<0.001) and a significant and continuous decrease in serum iPTH concentration (p<0. 001).
          • Key findings · abstract:Yogurt and the calcium carbonate pill induced a similar but less significant effect, increasing serum ionized calcium (p[excerpt truncated in our database — see source]
          • +1 more quotes in Studies
        • HumanComparative study of the intestinal absorption of three salts of calcium in young and elderly women.
          J Endocrinol Invest, 1998 · n n = 7 · [PMID 9624602]
          • Key findings · abstract:We have compared the digestive absorption of calcium (Ca) citrate in soluble and solid form and calcium gluconolactate-carbonate in 15 young and 20 elderly, healthy women using the oral calcium loading test.
          • Key findings · abstract:In the first group, the absorption of solid Ca citrate (1000 mg Ca element) was compared to the absorption of Ca gluconolactate-carbonate (1000 mg Ca element) both in young (n = 7) and elderly women (n = 10).
          • Key findings · abstract:In the second group, the absorption of soluble Ca citrate (1000 mg Ca element) was compared to the absorption of Ca gluconolactate-carbonate (1000 mg Ca element) in young (n = 8)
        • HumanIntestinal calcium absorption from different calcium preparations: influence of anion and solubility.
          Osteoporos Int, 1996 · n 18 healthy volunteers · [PMID 8931033]
          • Key findings · abstract:In the present study, the bioavailability of calcium citrate and calcium lactogluconate/carbonate from a therapeutic dose (= 500 mg Ca2+) was compared in men aged between 45 and 60 years on an intra-individual basis.
          • Key findings · abstract:Using a double-isotope method, the intestinal absorption from the three preparations was determined in randomized order at intervals of 2-4 weeks.
          • Key findings · abstract:The intestinal calcium absorption was then determined after 24 h on the basis of the ratio of the two isotopes in the plasma.
          • +1 more quotes in Studies
        • HumanFluoride bioavailability from immediate-release sodium fluoride with calcium carbonate compared with slow-release sodium fluoride with calcium citrate.
          Bone Miner, 1991 · [PMID 1912761]
          • Key findings · abstract:The circadian variation in serum fluoride was compared between treatment with immediate-release sodium fluoride (IR-NaF) (30 mg) and calcium carbonate (500 mg calcium) and slow-release sodium fluoride (SR-NaF) (25 mg) and calcium citrate (400 mg calcium) in seven patients with postmenopausal osteoporosis maintained on long-term fluoride treatment.
          • Key findings · abstract:During 12 h following a dose of SR-NaF, serum fluoride levels could be largely kept within the therapeutic window (believed to be 95-190 ng/ml or 5-10 mumol/l).
          • Key findings · abstract:Compared to SR-NaF, IR-NaF caused a significantly higher peak fluoride concentration[excerpt truncated in our database — see source]
          • +1 more quotes in Studies
        • HumanCalcium supplementation: effect on iron absorption.
          Am J Clin Nutr, 1991 · [PMID 1984334]
          • Key findings · abstract:The influence of calcium supplements on the absorption of dietary nonheme iron and of iron supplements was evaluated in 61 normal volunteer subjects by use of a double-radioisotope technique.
          • Key findings · abstract:When taken without food, calcium carbonate did not inhibit the absorption of ferrous sulphate with doses of either 300 mg Ca and 37 mg Fe or 600 mg Ca and 18 mg Fe.
          • Key findings · abstract:However, at the latter levels, calcium citrate and calcium phosphate reduced iron absorption significantly by 49% and 62%, respectively.
          • +1 more quotes in Studies
        • HumanSuperior calcium absorption from calcium citrate than calcium carbonate using external forearm counting.
          J Am Coll Nutr, 1990 · [PMID 2273192]
          • Key findings · abstract:Calcium absorption from calcium citrate was compared with that obtained from calcium carbonate in 20 normal women.
          • Key findings · abstract:It was measured by external forearm counting technique, where the ratio of forearm radioactivity after an oral dose of labeled calcium salt (containing 500 mg calcium) and after an intravenous injection of trace radiocalcium represented fractional calcium absorption.
          • Key findings · abstract:The fractional calcium absorption from calcium citrate was 39.2 +/- 8.6%, which was significantly higher than the 31.2 +/- 9.4% derived from calcium carbonate (p less than 0.001).
        • HumanDose dependency of calcium absorption: a comparison of calcium carbonate and calcium citrate.
          J Bone Miner Res, 1988 · n 4 men · [PMID 3213620]
          • Key findings · abstract:Using the well-described oral calcium load technique, we measured the calcium absorption from three different calcium doses (0.5, 1.0, and 2.0 g) of both calcium carbonate and calcium citrate administered to 21 normal subjects (4 men and 17 women, 22-60 years).
          • Key findings · abstract:The increment in urinary calcium post-load, reflective of intestinal calcium absorption, rose rapidly from 0 to 0.5 g calcium loads with only slight subsequent increases from the 0.5 g to 2.0 g calcium doses.
          • Key findings · abstract:The increment in urinary calcium (during the second 2 hr) following calcium citrate load (0.5 g calcium) was 0.104 +/- 0.096[excerpt truncated in our database — see source]
        • HumanGastrointestinal absorption of calcium from milk and calcium salts.
          N Engl J Med, 1987 · [PMID 3614304]
          • Key findings · abstract:Using a method by which the net absorption of calcium can be accurately measured after a single dose, we studied eight healthy fasting subjects after they took a 500-mg dose of calcium from each of five calcium salts with various degrees of water solubility and from milk.
          • Key findings · abstract:The mean (+/- SEM) net calcium absorption, in decreasing order of the solubility of the salts, was 32 +/- 4 percent from calcium acetate, 32 +/- 4 percent from calcium lactate, 27 +/- 3 percent from calcium gluconate, 30 +/- 3 percent from calcium citrate, and 39 +/- 3 percent from calcium carbonate.
          • Key findings · abstract:Calcium absorption fr[excerpt truncated in our database — see source]
          • +1 more quotes in Studies
        • HumanCalcium bioavailability from calcium carbonate and calcium citrate.
          J Clin Endocrinol Metab, 1985 · [PMID 4008614]
          • Key findings · abstract:The urinary calcium following calcium citrate load significantly higher (by 20-66%), whether expressed as the total amount or as the increment above basal (fasting) excretion.
          • Food effect · abstract:The urinary calcium following calcium citrate load significantly higher (by 20-66%), whether expressed as the total amount or as the increment above basal (fasting) excretion.
        • HumanCalcium absorption and achlorhydria.
          N Engl J Med, 1985 · [PMID 4000241]
          • Key findings · abstract:I compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects.
          • Key findings · abstract:Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier.
          • Key findings · abstract:Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001).
          • +2 more quotes in Studies
        • HumanAn evaluation of the importance of gastric acid secretion in the absorption of dietary calcium.
          J Clin Invest, 1984 · [PMID 6707197]
          • Key findings · abstract:Since calcium solubility is a prerequisite to calcium absorption, and since solubility of calcium is highly pH-dependent, it has been generally assumed that gastric acid secretion and gastric acidity play an important role in the intestinal absorption of calcium from ingested food or calcium salts such as CaCO3.
          • Key findings · abstract:Moreover, calcium absorption after CaCO3 ingestion was the same when intragastric contents were maintained at pH 7.4 (by in vivo titration) as when intragastric pH was 3.0.

        Measured absorption data (full-text extraction)

        97 papers read in full text, 77 with usable data (20 excluded as off-topic, reviews or off-target). 879 values extracted. Species: Human 55In vitro 19Rodent 3

        Grades: draft — pending reviewer (Dr. Colin Reily). Directions are auto-parsed from author statements; values are copied exactly as printed, never converted or estimated.

        Forms with measured values

        FormStudiesValuesAbsorption evidence gradeSpecies
        Carbonate23127Grade AA: well characterized in people. Forms: 5+ human studies, 100+ participants, randomized/crossover designs, consistent values. Comparisons: agreeing head-to-head and matched single-form evidence with clear separation. All grades are drafts pending reviewer sign-off.
        16 human studies, total n=369, 15 randomized/crossover; median CV 63.400000000000006% across 2 matched set(s) (consistent)
        		Human×21Rodent×1In vitro×1
        Citrate1691Grade AA: well characterized in people. Forms: 5+ human studies, 100+ participants, randomized/crossover designs, consistent values. Comparisons: agreeing head-to-head and matched single-form evidence with clear separation. All grades are drafts pending reviewer sign-off.
        8 human studies, total n=266, 8 randomized/crossover; median CV 63.0% across 2 matched set(s) (consistent)
        		Human×15In vitro×1
        Citrate malate374Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.
        3 human studies, total n=30, 2 randomized/crossover; consistency not evaluable (no matched set with ≥2 studies)
        		Human×3

        Single-form studies count as evidence for that form. Form tags are keyword-matched from arm descriptions and need reviewer confirmation.

        Head-to-head comparisons

        Grade CC: limited or conflicting human data: 1–2 studies, head-to-head and single-form evidence disagree, or baseline correction not reported. All grades are drafts pending reviewer sign-off.Citrate vs Carbonatecombined head-to-head + matched single-form grade

        head-to-head only; no matched single-form separation. H2H: C (12 human studies (12 randomized/crossover); majority: first form higher (7 agree, 4 contradict)); indirect: none

        StudyComparisonParameterAuthor-stated resultp
        Human PMID 1912761B vs ACmax, AUC, ΔAUC, urinary fluorideIR-NaF + CaCO3 > SR-NaF + Ca citrate
        “the immediate-release sodium fluoride produced a significantly greater peak concentration of fluoride in serum, area under the curve, and urinary fluoride” (Table 1)
        		<0.05
        Human PMID 1912761B vs Aserum fluoride at each timeIR > SR at all times except 12 h
        “serum fluoride levels were significantly higher ... at all time periods, except at 12 h” (Results p.4; Fig. 1)
        		<0.05
        Human PMID 3213620Ca citrate vs Ca carbonate, all loads, urinary Ca increment second 2 hurinary_excretioncitrate > carbonate at 0.2, 0.5, 1.0, 2.0 g
        “calcium absorption from calciiim citrate was higher than from calcium carbonate at all calcium loads” (Results; Fig. 1 (significant at 0.5, 1.0 and 2.0 g))
        		<0.05
        Human PMID 3213620Ca citrate 0.5 g vs Ca carbonate 2.0 gurinary_excretioncitrate 0.5 g > carbonate 2.0 g
        “calcium absorption from 0.5 g of calcium as calcium citrate is greater than that from 2.0 g of calcium as calcium carbonate” (Abstract; Results)
        		NR
        Human PMID 3213620Ca citrate vs Ca carbonate, first 2 h urinary Ca incrementurinary_excretioncitrate > carbonateNR
        Human PMID 3213620Ca citrate vs Ca carbonate, 4-h urinary Caurinary_excretioncitrate > carbonateNR
        Human PMID 3213620Ca citrate vs Ca carbonate, serum Ca increment 0 to 4 hchange_from_baselinecitrate > carbonate at 0.5, 1.0, 2.0 gNR
        Human PMID 3213620Ca citrate vs Ca carbonate, fractional absorption by 47Ca fecal recoveryfractional_absorptioncitrate > carbonate<0.05
        Human PMID 3614304Carbonate vs acetate vs lactate vs gluconate vs citrate vs milknet calcium absorptionno significant difference
        “Absorption from various salts and absorption from milk were not significantly different (P = 0.22) from one another as tested by analysis of variance.” (Results p.3; Abstract)
        		0.22
        Human PMID 4000241A-CIT vs A-CARB (fasting, achlorhydric)fractional_absorptioncitrate > carbonate
        “0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001)” (Abstract)
        		<0.0001
        Human PMID 4000241N-CIT vs N-CARB (fasting, normal)fractional_absorptionno difference
        “0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not significant)” (Abstract)
        		NS
        Human PMID 4000241A-CARB vs normal-subject values and vs both citrate arms (Table 1)fractional_absorptionachlorhydric carbonate lower than the other three means
        “Significantly lower than the other three means, P<0.001 (t-test).” (Table 1 footnote)
        		<0.001
        Human PMID 10501794PM vs CCionized calcium AUCPM > CC
        “after PM intake the ionized calcium AUC was 51% larger than that after CC” (Fig. 1 legend)
        		<0.01
        Human PMID 10501794PM vs CCiPTH AUCPM differs from CC (greater PTH suppression per authors)<0.05
        Human PMID 10579145A vs BΔAUCCitracal > Os-Cal
        “∆AUC of Citracal was significantly greater than that of Os-Cal by about 2.5-fold.” (Table I; Results)
        		<0.0167
        Human PMID 10579145A vs Bpeak-basal variationCitracal > Os-Cal
        “The peak-basal variation in serum calcium of Citracal was significantly greater than that of Os-Cal by 76%” (Table I; Results)
        		<0.0167
        Human PMID 10579145A vs Bincrement in serum calcium at 1, 4, 5 hCitracal > Os-Cal
        “the increment in serum calcium for Citracal was significantly greater than that of Os-Cal at 1, 4, and 5 hours” (Results p.2; Fig. 1)
        		NR
        Human PMID 11075309A (citrate) vs B (carbonate)ΔAUC serum Ca (placebo-subtracted)citrate > carbonate
        “∆AUC, mg/dl/4-6 h 0.88 ± 1.85 1.71 ± 1.51 0.01” (Table I)
        		0.01
        Human PMID 11075309A vs Bpeak-basal variation serum Cacitrate > carbonate0.02
        Human PMID 11075309A vs Btmax serum Cano significant difference
        “The tmax for serum calcium did not significantly differ between calcium carbonate and calcium citrate.” (Table I)
        		0.07
        Human PMID 11075309A vs Bcumulative increment urinary Ca/Cr (placebo-subtracted)citrate > carbonate0.03
        Human PMID 11075309A vs BΔAOC serum PTHgreater decrement with citrate0.009
        Human PMID 11075309A vs Bbasal-nadir variation serum PTHgreater decrement with citrate0.02
        Human PMID 11075309A vs Btmin serum PTHno difference1.00
        Human PMID 11075309A vs B (not placebo-subtracted)serum Ca response curvecitrate > carbonate
        “The response curve of calcium citrate showed a significantly greater rise compared with that of calcium carbonate (p < 0.0001).” (Results p.1239; Fig. 1)
        		< 0.0001
        Human PMID 11075309A vs B (not placebo-subtracted)cumulative increment urinary Cacitrate > carbonate
        “the cumulative increment in urinary calcium of calcium citrate was greater than that of calcium carbonate (p = 0.02)” (Results p.1240; Fig. 4)
        		0.02
        Human PMID 11274906calcium citrate vs calcium carbonateuCal/uCrno difference between preparations
        “no significant difference was observed” (Results 4.3)
        		NR
        Human PMID 11274906citrate-day vs carbonate-day basalbasal uCal/uCrno difference.777
        Human PMID 12412824B vs A, estrogen treatment: No (n = 15)∆AUC serum Cacitrate > carbonate
        “significantly higher than that of calcium carbonate in the 15 women who were not taking estrogen” (Results; Fig. 1A)
        		NR
        Human PMID 12412824B vs A, estrogen treatment: Yes (n = 10)∆AUC serum Cano difference
        “∆AUC was equal between the two formulations in the 10 women receiving estrogen” (Results)
        		NR
        Human PMID 12412824B vs A, 25OHD < 15 ng/ml (n = 12)∆AUC serum Cacitrate > carbonate
        “Bioavailability of calcium citrate was significantly higher than that of calcium carbonate in the subgroups with lower serum 25OHD” (Results; Fig. 1B)
        		NR
        Human PMID 12412824B vs A, 1,25-(OH)2 D ≥ 28 pg/ml (n = 13)∆AUC serum Cacitrate > carbonate
        “and higher serum 1,25-(OH)2 D.” (Results; Fig. 1C)
        		NR
        Human PMID 12412824B vs A, 1,25-(OH)2 D < 28 pg/ml (n = 12)∆AUC serum Casimilar relationship, not significant
        “this did not reach significance because of three outliers” (Results)
        		NR
        Human PMID 12672710Os-Cal (carbonate) vs Citracal (citrate), within each studyabsorption indicesbioequivalent
        “the two marketed products tested were found to be bioequivalent, with nearly identical (and nonsignificantly different) indices of absorption” (Methods p.143)
        		NR
        Human PMID 15734899Citrate vs. carbonateserum calcium (% of time 0, main effect)see F
        “Citrate vs. carbonate 15.432 0.002” (Table 1)
        		0.002
        Human PMID 15734899Citrate vs. carbonateserum iPTH (% of time 0, main effect)see F
        “Citrate vs. carbonate ... 12.433 0.004” (Table 1)
        		0.004
        Human PMID 15734899Citrate vs placebo / carbonateΔAUC 0-270 mincitrate > placebo and carbonate
        “whereas the latter was only modestly greater than either placebo (107; p < 0.05) or calcium carbonate (91; p < 0.05)” (Abstract)
        		<0.05
        Human PMID 15734899Citrate vs placebo / carbonate at 180-270 minserum calciumcitrate greater
        “the increases following calcium citrate were significantly greater than those for the placebo [F(1,13) = 16.508, p = 0.001] or calcium carbonate” (Results p.1219)
        		0.001 (placebo); <0.01 (carbonate)
        Human PMID 39603923citrate vs carbonateserum Ca AUC0-8hcitrate > carbonate
        “higher AUC0-8h of 76.1 mg/dL·h versus 74.7 mg/dL·h for carbonate” (Table 3; Table 4)
        		.001 (unadjusted); .043 (adjusted)
        Human PMID 39603923citrate vs carbonateserum Ca Cmaxcitrate > carbonate
        “a Cmax of 9.8 mg/dL compared to 9.5 mg/dL for carbonate” (Table 3; Table 4)
        		<.001 (unadjusted); .004 (adjusted)
        Human PMID 39603923citrate vs carbonateserum Ca 3-6 hcitrate > carbonate
        “From 3 to 6 hours postadministration, the citrate salt led to significantly higher serum Ca levels than carbonate” (Table 2)
        		<.001 to .001
        Human PMID 39603923citrate vs carbonatecumulative 9-h urinary Cacitrate > carbonate
        “Ca citrate had a significantly higher cumulative urinary Ca excretion (MD = 19.7 mg/dL, 95% CI: 18.3 to 21.0” (Table 3; Table 6)
        		<.001
        Human PMID 39603923citrate vs carbonatePTH AUC0-8h / PTHmincitrate lower
        “The use of Ca citrate significantly decreased PTH compared to Ca carbonate” (Table 3; Table 5)
        		<.001 (unadjusted); .028/.024 (adjusted)
        Cmax, Tmax and AUC by study arm (217 values)
        StudyArm / formDoseFednAnalyteParamValueUnitsSource
        Human 10501794Calcium-citrate-enriched powdered milk
        28 g calcium-citrate-enriched powdered milk dissolved in 0.2 l water
        		500 mg (elemental)light neutral breakfast after 12-h fast19ionized calcium (serum)AUC
        ionized Ca AUC, PM larger than CC (percent as printed)
        		51% % largerFig. 1 legend; Results p.139
        Human 10501794Calcium-citrate-enriched powdered milk
        28 g calcium-citrate-enriched powdered milk dissolved in 0.2 l water
        		500 mg (elemental)light neutral breakfast after 12-h fast19ionized calcium (serum)AUC
        ionized Ca AUC, PM larger than YO (percent as printed)
        		54% % largerFig. 1 legend; Results p.139
        Human 10501794Calcium-citrate-enriched powdered milk
        28 g calcium-citrate-enriched powdered milk dissolved in 0.2 l water
        		500 mg (elemental)light neutral breakfast after 12-h fast19ionized calcium (serum)AUC
        ionized Ca AUC, PM larger than LM (percent as printed)
        		70% % largerFig. 1 legend; Results p.139
        Human 10501794
        		 ionized calcium (serum)AUC
        ionized Ca AUC, YO/CC larger than LM (percent as printed)
        		37% % largerFig. 1 legend
        Human 10501794Calcium-citrate-enriched powdered milk
        28 g calcium-citrate-enriched powdered milk dissolved in 0.2 l water
        		500 mg (elemental)light neutral breakfast after 12-h fast19intact PTH (serum)AUC
        iPTH AUC, PM versus YO (percent as printed)
        		27% % largerFig. 2 legend; Results p.139
        Human 10501794Calcium-citrate-enriched powdered milk
        28 g calcium-citrate-enriched powdered milk dissolved in 0.2 l water
        		500 mg (elemental)light neutral breakfast after 12-h fast19intact PTH (serum)AUC
        iPTH AUC, PM versus CC (percent as printed)
        		31% % largerFig. 2 legend; Results p.139
        Human 10501794Calcium-citrate-enriched powdered milk
        28 g calcium-citrate-enriched powdered milk dissolved in 0.2 l water
        		500 mg (elemental)light neutral breakfast after 12-h fast19intact PTH (serum)AUC
        iPTH AUC, PM versus LM (percent as printed)
        		45% % largerFig. 2 legend; Results p.139
        Human 10501794
        		 intact PTH (serum)AUC
        iPTH AUC, YO/CC versus LM (percent as printed)
        		20% % largerFig. 2 legend
        Human 10579145Citracal
        calcium citrate tablets (2 x 250 mg calcium)
        		500 mg calcium (elemental)with breakfast18total serum calcium (serum)AUC
        ΔAUC in serum calcium from preload over 4-6 h
        		1.82 ± 0.25 (SD)mg Ca•4-6 h/dlTable I
        Human 10579145Os-Cal
        calcium carbonate tablet (1 x 500 mg calcium)
        		500 mg calcium (elemental)with breakfast18total serum calcium (serum)AUC
        ΔAUC in serum calcium from preload over 4-6 h
        		0.72 ± 0.37 (SD)mg Ca•4-6 h/dlTable I
        Human 10579145Placebo
        two placebo tablets identical in appearance to Citracal
        		0 mg calcium (NR)with breakfast18total serum calcium (serum)AUC
        ΔAUC in serum calcium from preload over 4-6 h
        		0.19 ± 0.24 (SD)mg Ca•4-6 h/dlTable I
        Human 10579145Citracal
        calcium citrate tablets (2 x 250 mg calcium)
        		500 mg calcium (elemental)with breakfast18total serum calcium (serum)Cmax
        peak-basal variation in serum calcium (peak minus preload)
        		0.67 ± 0.10 (SD)mg/dlTable I
        Human 10579145Os-Cal
        calcium carbonate tablet (1 x 500 mg calcium)
        		500 mg calcium (elemental)with breakfast18total serum calcium (serum)Cmax
        peak-basal variation in serum calcium (peak minus preload)
        		0.38 ± 0.08 (SD)mg/dlTable I
        Human 10579145Placebo
        two placebo tablets identical in appearance to Citracal
        		0 mg calcium (NR)with breakfast18total serum calcium (serum)Cmax
        peak-basal variation in serum calcium (peak minus preload)
        		0.27 ± 0.06 (SD)mg/dlTable I
        Human 10579145Citracal
        calcium citrate tablets (2 x 250 mg calcium)
        		500 mg calcium (elemental)with breakfast18total serum calcium (serum)Tmax
        time to peak increment in serum calcium
        		4.44 ± 0.27 (SD)hTable I
        Human 10579145Os-Cal
        calcium carbonate tablet (1 x 500 mg calcium)
        		500 mg calcium (elemental)with breakfast18total serum calcium (serum)Tmax
        time to peak increment in serum calcium
        		3.89 ± 0.36 (SD)hTable I
        Human 10579145Placebo
        two placebo tablets identical in appearance to Citracal
        		0 mg calcium (NR)with breakfast18total serum calcium (serum)Tmax
        time to peak increment in serum calcium
        		3.34 ± 0.35 (SD)hTable I
        Human 11075309Calcium carbonate (Os-Cal 500 + D)
        Calcium carbonate tablet, one tablet 500 mg elemental calcium and 125 IU vitamin D
        		500 mg (elemental)fed (standard breakfast)25serum calcium (serum)AUC
        ΔAUC serum Ca above preload baseline, minus placebo
        		0.88 ± 1.85 (SD)mg/dl/4-6 hTable I
        Human 11075309Calcium citrate (Citracal 250 mg + D)
        Calcium citrate tablets, two tablets each 250 mg elemental calcium and 62.5 IU vitamin D
        		500 mg (elemental)fed (standard breakfast)25serum calcium (serum)AUC
        ΔAUC serum Ca above preload baseline, minus placebo
        		1.71 ± 1.51 (SD)mg/dl/4-6 hTable I
        Human 11075309Calcium carbonate (Os-Cal 500 + D)
        Calcium carbonate tablet, one tablet 500 mg elemental calcium and 125 IU vitamin D
        		500 mg (elemental)fed (standard breakfast)25serum calcium (serum)Cmax
        peak-basal variation in serum Ca (Cmax minus baseline), minus placebo
        		0.46 ± 0.36 (SD)mg/dlTable I
        Human 11075309Calcium citrate (Citracal 250 mg + D)
        Calcium citrate tablets, two tablets each 250 mg elemental calcium and 62.5 IU vitamin D
        		500 mg (elemental)fed (standard breakfast)25serum calcium (serum)Cmax
        peak-basal variation in serum Ca (Cmax minus baseline), minus placebo
        		0.67 ± 0.43 (SD)mg/dlTable I
        Human 11075309Calcium carbonate (Os-Cal 500 + D)
        Calcium carbonate tablet, one tablet 500 mg elemental calcium and 125 IU vitamin D
        		500 mg (elemental)fed (standard breakfast)25serum calcium (serum)Tmax
        tmax serum Ca, minus placebo
        		2.9 ± 1.7 (SD)hTable I
        Human 11075309Calcium citrate (Citracal 250 mg + D)
        Calcium citrate tablets, two tablets each 250 mg elemental calcium and 62.5 IU vitamin D
        		500 mg (elemental)fed (standard breakfast)25serum calcium (serum)Tmax
        tmax serum Ca, minus placebo
        		3.7 ± 1.6 (SD)hTable I
        Human 11444420Os-Cal
        calcium carbonate (oyster shell) + 200 IU vitamin D tablet
        		503 mg (elemental)fed (breakfast)24total serum calcium (serum)AUC
        Increment AUC0-5h (AUC5)
        		1.81 ± 0.22 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Os-Cal
        calcium carbonate (oyster shell) + 200 IU vitamin D tablet
        		503 mg (elemental)fed (breakfast)24total serum calcium (serum)AUC
        Increment AUC0-24h (AUC24)
        		6.69 ± 1.07 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Os-Cal
        calcium carbonate (oyster shell) + 200 IU vitamin D tablet
        		503 mg (elemental)fed (breakfast)24total serum calcium (serum)Cmax
        Cmax (observed)
        		10.3 ± 0.07 (SEM)mg/dLTable 1 (p.242)
        Human 11444420Os-Cal
        calcium carbonate (oyster shell) + 200 IU vitamin D tablet
        		503 mg (elemental)fed (breakfast)24total serum calcium (serum)Tmax
        Tmax (observed)
        		4.8 ± 0.51 (SEM)hoursTable 1 (p.242)
        Human 11444420Citracal
        calcium citrate (combination of 200 mg Ca and 315 mg Ca + 200 IU D formulations)
        		516 mg (elemental)fed (breakfast)24total serum calcium (serum)AUC
        Increment AUC0-5h (AUC5)
        		1.88 ± 0.18 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Citracal
        calcium citrate (combination of 200 mg Ca and 315 mg Ca + 200 IU D formulations)
        		516 mg (elemental)fed (breakfast)24total serum calcium (serum)AUC
        Increment AUC0-24h (AUC24)
        		5.91 ± 1.02 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Citracal
        calcium citrate (combination of 200 mg Ca and 315 mg Ca + 200 IU D formulations)
        		516 mg (elemental)fed (breakfast)24total serum calcium (serum)Cmax
        Cmax (observed)
        		10.3 ± 0.08 (SEM)mg/dLTable 1 (p.242)
        Human 11444420Citracal
        calcium citrate (combination of 200 mg Ca and 315 mg Ca + 200 IU D formulations)
        		516 mg (elemental)fed (breakfast)24total serum calcium (serum)Tmax
        Tmax (observed)
        		4.2 ± 0.36 (SEM)hoursTable 1 (p.242)
        Human 11444420CaCO3 (precipitated, encapsulated)
        laboratory-precipitated calcium carbonate in gelatin capsule, no excipients
        		497 mg (elemental)fed (breakfast)23total serum calcium (serum)AUC
        Increment AUC0-5h (AUC5)
        		1.95 ± 0.15 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420CaCO3 (precipitated, encapsulated)
        laboratory-precipitated calcium carbonate in gelatin capsule, no excipients
        		497 mg (elemental)fed (breakfast)23total serum calcium (serum)AUC
        Increment AUC0-24h (AUC24)
        		6.39 ± 0.85 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420CaCO3 (precipitated, encapsulated)
        laboratory-precipitated calcium carbonate in gelatin capsule, no excipients
        		497 mg (elemental)fed (breakfast)23total serum calcium (serum)Cmax
        Cmax (observed)
        		10.3 ± 0.07 (SEM)mg/dLTable 1 (p.242)
        Human 11444420CaCO3 (precipitated, encapsulated)
        laboratory-precipitated calcium carbonate in gelatin capsule, no excipients
        		497 mg (elemental)fed (breakfast)23total serum calcium (serum)Tmax
        Tmax (observed)
        		4.1 ± 0.32 (SEM)hoursTable 1 (p.242)
        Human 11444420Blank
        empty gelatin capsule
        		0 mg (NR)fed (breakfast)24total serum calcium (serum)AUC
        Increment AUC0-5h (AUC5)
        		0.04 ± 0.14 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Blank
        empty gelatin capsule
        		0 mg (NR)fed (breakfast)24total serum calcium (serum)AUC
        Increment AUC0-24h (AUC24)
        		-0.05 ± 0.77 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Os-Cal
        calcium carbonate (oyster shell) + 200 IU vitamin D tablet
        		503 mg (elemental)fed (breakfast)24serum ionized calcium (serum)AUC
        Increment AUC0-5h (AUC5)
        		0.83 ± 0.11 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Os-Cal
        calcium carbonate (oyster shell) + 200 IU vitamin D tablet
        		503 mg (elemental)fed (breakfast)24serum ionized calcium (serum)AUC
        Increment AUC0-24h (AUC24)
        		2.36 ± 0.56 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Os-Cal
        calcium carbonate (oyster shell) + 200 IU vitamin D tablet
        		503 mg (elemental)fed (breakfast)24serum ionized calcium (serum)Cmax
        Cmax (observed)
        		5.3 ± 0.02 (SEM)mg/dLTable 1 (p.242)
        Human 11444420Os-Cal
        calcium carbonate (oyster shell) + 200 IU vitamin D tablet
        		503 mg (elemental)fed (breakfast)24serum ionized calcium (serum)Tmax
        Tmax (observed)
        		5.1 ± 0.91 (SEM)hoursTable 1 (p.242)
        Human 11444420Citracal
        calcium citrate (combination of 200 mg Ca and 315 mg Ca + 200 IU D formulations)
        		516 mg (elemental)fed (breakfast)24serum ionized calcium (serum)AUC
        Increment AUC0-5h (AUC5)
        		1.02 ± 0.11 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Citracal
        calcium citrate (combination of 200 mg Ca and 315 mg Ca + 200 IU D formulations)
        		516 mg (elemental)fed (breakfast)24serum ionized calcium (serum)AUC
        Increment AUC0-24h (AUC24)
        		3.58 ± 0.53 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Citracal
        calcium citrate (combination of 200 mg Ca and 315 mg Ca + 200 IU D formulations)
        		516 mg (elemental)fed (breakfast)24serum ionized calcium (serum)Cmax
        Cmax (observed)
        		5.4 ± 0.03 (SEM)mg/dLTable 1 (p.242)
        Human 11444420Citracal
        calcium citrate (combination of 200 mg Ca and 315 mg Ca + 200 IU D formulations)
        		516 mg (elemental)fed (breakfast)24serum ionized calcium (serum)Tmax
        Tmax (observed)
        		4.3 ± 0.43 (SEM)hoursTable 1 (p.242)
        Human 11444420CaCO3 (precipitated, encapsulated)
        laboratory-precipitated calcium carbonate in gelatin capsule, no excipients
        		497 mg (elemental)fed (breakfast)23serum ionized calcium (serum)AUC
        Increment AUC0-5h (AUC5)
        		0.85 ± 0.10 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420CaCO3 (precipitated, encapsulated)
        laboratory-precipitated calcium carbonate in gelatin capsule, no excipients
        		497 mg (elemental)fed (breakfast)23serum ionized calcium (serum)AUC
        Increment AUC0-24h (AUC24)
        		2.58 ± 0.46 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420CaCO3 (precipitated, encapsulated)
        laboratory-precipitated calcium carbonate in gelatin capsule, no excipients
        		497 mg (elemental)fed (breakfast)23serum ionized calcium (serum)Cmax
        Cmax (observed)
        		5.3 ± 0.03 (SEM)mg/dLTable 1 (p.242)
        Human 11444420CaCO3 (precipitated, encapsulated)
        laboratory-precipitated calcium carbonate in gelatin capsule, no excipients
        		497 mg (elemental)fed (breakfast)23serum ionized calcium (serum)Tmax
        Tmax (observed)
        		3.1 ± 0.26 (SEM)hoursTable 1 (p.242)
        Human 11444420Blank
        empty gelatin capsule
        		0 mg (NR)fed (breakfast)24serum ionized calcium (serum)AUC
        Increment AUC0-5h (AUC5)
        		-0.05 ± 0.09 (SEM)mg/dL·hourTable 1 (p.242)
        Human 11444420Blank
        empty gelatin capsule
        		0 mg (NR)fed (breakfast)24serum ionized calcium (serum)AUC
        Increment AUC0-24h (AUC24)
        		0.47 ± 0.56 (SEM)mg/dL·hourTable 1 (p.242)
        Human 12412824Calcium carbonate
        calcium carbonate
        		500 mg (elemental)NR25serum calcium (serum)AUC
        ∆AUC of serum Ca after subtraction of placebo phase; subgroup: Estrogen treatment: Yes
        		1.58 ± 25th –0.10, 75th 2.80 (IQR)mg/dl • 4-6 hTable I
        Human 12412824Calcium citrate
        calcium citrate
        		500 mg (elemental)NR25serum calcium (serum)AUC
        ∆AUC of serum Ca after subtraction of placebo phase; subgroup: Estrogen treatment: Yes
        		1.50 ± 25th 0.90, 75th 2.45 (IQR)mg/dl • 4-6 hTable I
        Human 12412824Calcium carbonate
        calcium carbonate
        		500 mg (elemental)NR25serum calcium (serum)AUC
        ∆AUC of serum Ca after subtraction of placebo phase; subgroup: Estrogen treatment: No
        		0.25 ± 25th –0.60, 75th 1.30 (IQR)mg/dl • 4-6 hTable I
        Human 12412824Calcium citrate
        calcium citrate
        		500 mg (elemental)NR25serum calcium (serum)AUC
        ∆AUC of serum Ca after subtraction of placebo phase; subgroup: Estrogen treatment: No
        		0.85 ± 25th 0.70, 75th 3.25 (IQR)mg/dl • 4-6 hTable I
        Human 12412824Calcium carbonate
        calcium carbonate
        		500 mg (elemental)NR25serum calcium (serum)AUC
        ∆AUC of serum Ca after subtraction of placebo phase; subgroup: 25OHD < 15 ng/ml
        		–0.10 ± 25th –0.98, 75th 1.33 (IQR)mg/dl • 4-6 hTable I
        Human 12412824Calcium citrate
        calcium citrate
        		500 mg (elemental)NR25serum calcium (serum)AUC
        ∆AUC of serum Ca after subtraction of placebo phase; subgroup: 25OHD < 15 ng/ml
        		0.98 ± 25th 0.75, 75th 2.15 (IQR)mg/dl • 4-6 hTable I
        Human 12412824Calcium carbonate
        calcium carbonate
        		500 mg (elemental)NR25serum calcium (serum)AUC
        ∆AUC of serum Ca after subtraction of placebo phase; subgroup: 25OHD ≥ 15 ng/ml
        		1.20 ± 25th 0.30, 75th 2.70 (IQR)mg/dl • 4-6 hTable I
        Human 12412824Calcium citrate
        calcium citrate
        		500 mg (elemental)NR25serum calcium (serum)AUC
        ∆AUC of serum Ca after subtraction of placebo phase; subgroup: 25OHD ≥ 15 ng/ml
        		1.75 ± 25th 0.70, 75th 3.05 (IQR)mg/dl • 4-6 hTable I
        Human 12412824Calcium carbonate
        calcium carbonate
        		500 mg (elemental)NR25serum calcium (serum)AUC
        ∆AUC of serum Ca after subtraction of placebo phase; subgroup: 1,25-(OH)2 D < 28 pg/ml
        		0.28 ± 25th –0.28, 75th 2.03 (IQR)mg/dl • 4-6 hTable I

        Showing 60 of 217 Cmax/Tmax/AUC values (human first). All 879 values are in /api/supplements/calcium.

        References for this section (13)
        1. Human Talbot JR, Guardo P, Seccia S, Gear L, Lubary DR, Saad G, Roberts ML, Fradinger E, Marino A, Zanchetta JR. Calcium bioavailability and parathyroid hormone acute changes after oral intake of dairy and nondairy products in healthy volunteers. Osteoporosis international : a journal established as result of cooperation between the European Foundation for Osteoporosis and the National Osteoporosis Foundation of the USA. 1999;10(2):137-42. PMID 10501794. doi:10.1007/s001980050208 PubMed · DOI · randomized crossover (administration order randomly assigned; five kinetic studies per subject, one every other day), n=19
        2. Human Heller HJ, Stewart A, Haynes S, Pak CY. Pharmacokinetics of calcium absorption from two commercial calcium supplements. Journal of clinical pharmacology. 1999;39(11):1151-4. PMID 10579145. PubMed · randomized crossover, n=18
        3. Human Heller HJ, Greer LG, Haynes SD, Poindexter JR, Pak CY. Pharmacokinetic and pharmacodynamic comparison of two calcium supplements in postmenopausal women. Journal of clinical pharmacology. 2000;40(11):1237-44. PMID 11075309. PubMed · randomized crossover, n=25
        4. Human Heaney RP, Dowell MS, Bierman J, Hale CA, Bendich A. Absorbability and cost effectiveness in calcium supplementation. Journal of the American College of Nutrition. 2001;20(3):239-46. PMID 11444420. doi:10.1080/07315724.2001.10719038 PubMed · DOI · randomized crossover (four-period, three-way; 4th period precipitated CaCO3 not in random order), n=24
        5. Human Heller HJ, Poindexter JR, Adams-Huet B. Effect of estrogen treatment and vitamin D status on differing bioavailabilities of calcium carbonate and calcium citrate. Journal of clinical pharmacology. 2002;42(11):1251-6. PMID 12412824. doi:10.1177/009127002762491343 PubMed · DOI · randomized crossover (retrospective subgroup analysis of previously published trial), n=25
        6. Human Sakhaee K, Pak CY. Fluoride bioavailability from immediate-release sodium fluoride with calcium carbonate compared with slow-release sodium fluoride with calcium citrate. Bone and mineral. 1991;14(2):131-6. PMID 1912761. doi:10.1016/0169-6009(91)90090-m PubMed · DOI · open-label, non-randomized two-phase crossover (fixed order), n=7
        7. Human Harvey JA, Zobitz MM, Pak CY. Dose dependency of calcium absorption: a comparison of calcium carbonate and calcium citrate. Journal of bone and mineral research : the official journal of the American Society for Bone and Mineral Research. 1988;3(3):253-8. PMID 3213620. doi:10.1002/jbmr.5650030303 PubMed · DOI · randomized crossover (9 phases in random order, at least 3 days apart; blinded capsules), n=21
        8. Human Sheikh MS, Santa Ana CA, Nicar MJ, Schiller LR, Fordtran JS. Gastrointestinal absorption of calcium from milk and calcium salts. The New England journal of medicine. 1987;317(9):532-6. PMID 3614304. doi:10.1056/NEJM198708273170903 PubMed · DOI · randomized crossover (random order of placebo, 5 salts and milk within each subject), n=8
        9. Human Recker RR. Calcium absorption and achlorhydria. The New England journal of medicine. 1985;313(2):70-3. PMID 4000241. doi:10.1056/NEJM198507113130202 PubMed · DOI · randomized crossover (order of oral and intravenous doses random; each subject tested with both calcium salts)
        10. Human Song YM, Sheu WH, Lee WJ. Acute biochemical variations induced by calcium citrate and calcium carbonate in Type 2 diabetic patients: impaired calcium absorption in Type 2 diabetic patients with prolonged gastric emptying time. Journal of diabetes and its complications. 2001;15(2):97-102. PMID 11274906. doi:10.1016/s1056-8727(00)00128-8 PubMed · DOI · randomized crossover (two calcium preparations given on separate days in random order), n=16
        11. Human Heaney RP, Dowell MS, Hale CA, Bendich A. Calcium absorption varies within the reference range for serum 25-hydroxyvitamin D. Journal of the American College of Nutrition. 2003;22(2):142-6. PMID 12672710. doi:10.1080/07315724.2003.10719287 PubMed · DOI · two randomized crossover studies (Os-Cal vs Citracal) done ~1 year apart; analysis compares study with 25OHD pretreatment vs study without (independent groups plus 14 paired participants), n=34
        12. Human Hanzlik RP, Fowler SC, Fisher DH. Relative bioavailability of calcium from calcium formate, calcium citrate, and calcium carbonate. The Journal of pharmacology and experimental therapeutics. 2005;313(3):1217-22. PMID 15734899. doi:10.1124/jpet.104.081893 PubMed · DOI · other (four-way crossover, fixed non-randomized order: placebo, formate, carbonate, citrate), n=14
        13. Human Hany M, Wuyts S, Abouelnasr AA, Zidan A, Demerdash HM, Hussein HASM, Arida RE, Elsharkawi SM, Kramers C, Torensma B. Comparison of calcium citrate and calcium carbonate absorption in patients with a Roux-en-Y gastric bypass, sleeve gastrectomy, and one-anastomosis gastric bypass: a double-blind, randomized cross-over trial. Surgery for obesity and related diseases : official journal of the American Society for Bariatric Surgery. 2025;21(4):471-481. PMID 39603923. doi:10.1016/j.soard.2024.10.034 PubMed · DOI · randomized crossover (double-blind), n=150

        Indirect comparisons (across studies)

        Each form's values come from different human studies that tested one form only. Rows are compared only when parameter, analyte, matrix, fed/fasted state, single vs repeated dosing, AUC interval and units all match, and baseline correction matches where reported (a value with baseline correction not reported is labeled and capped at grade D). Serum and plasma are treated as the same matrix. Ranges are the lowest and highest printed values; nothing is averaged or pooled. Conditions a paper does not state are recorded as NR and never matched.

        Indirect comparison: weighs less than head-to-head evidence; comparisons using values with baseline correction not reported are capped at C. The combined grade for named pairs is shown in the head-to-head section. draft — pending reviewer (Dr. Colin Reily).

        No form pair for this supplement has matched-condition single-form human data yet.

        Pairs that cannot be compared indirectly yet

        • Carbonate vs Citrate: matched only within the same study
        • Carbonate vs Citrate malate: all arms come from the same studies (head-to-head only, see above)
        • Citrate vs Citrate malate: no matched condition set: arms differ on matrix
        Method
        Indirect (cross-study) PK comparisons from bundle_v2 single-form human arms.
Values are copied as printed. Matching key: parameter, analyte, matrix, fed/fasted, single vs repeated,
AUC interval (from parameter_detail), baseline correction, units (exact). No pooling/averaging: per-form
ranges are min–max of printed values. Analyte for minerals/B12 is classed as total element vs isotope/radiotracer; units compared after removing spaces/separators only; IV arms excluded; serum and plasma treated as the same matrix; curated magnesium v1 rows (mapped from stated conditions only, NR otherwise, deduped against the bundle) are included; baseline correction NR is treated as unknown (may match corrected or uncorrected sets; labeled and capped at C); for % absorption endpoints an unreported baseline correction is treated as not applicable. Normalization: value / elemental dose (mg) ONLY when dose_basis is
'elemental', dose unit is mg, single dose, baseline-corrected=yes, parameter Cmax/AUC. Grade capped at C.
Run after merge_bundle.py.

        Should you take Calcium with food?

        Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.human + animal data · drafthow we gradeSpecies (abstract screen): 63 human, 1 rodent

        Grade basis (abstract screen): 29 human randomized/crossover studies; A-eligible only once the reviewer confirms they agree (capped at B until then). Auto-computed draft grade — pending reviewer review.

        Show 64 studies with verbatim quotes
        • HumanPopulation pharmacokinetics of oral fosfomycin calcium in healthy women.
          J Antimicrob Chemother, 2024 · [PMID 39205651]
          • Key findings · abstract:METHODS: A clinical trial (a randomized, open-label, bioavailability study of single and multiple doses of 1000 mg capsules, single dose of 500 mg capsule and single dose of 250 mg/5 mL suspension of oral fosfomycin calcium under fasted conditions in healthy women volunteers, Code: PD7522.22, EudraCT: 2020-001664-28) was carried out at the Clinical Trial Unit, Araba University Hospital (Vitoria-Gasteiz, Spain).
          • Key findings · abstract:Twenty-four healthy women were included in the study, and plasma samples were collected at different times over a period of 24 h.
          • Key findings · abstract:The concentration-time data of fosfomycin in plasma[excerpt truncated in our database — see source]
          • +5 more quotes in Studies
        • HumanAn Algorithm to Assess Calcium Bioavailability from Foods.
          J Nutr, 2024 · [PMID 38072154]
          • Key findings · abstract:RESULTS: Data from 496 observations were modeled to develop a predictive algorithm for calcium bioavailability in adults on the basis of calcium load and oxalate and phytate loads, which represent the 2 main inhibitors of calcium absorption.
        • HumanComparative Effectiveness of Ascorbic Acid vs. Calcium Ascorbate Ingestion on Pharmacokinetic Profiles and Immune Biomarkers in Healthy Adults: A Preliminary Study.
          Nutrients, 2024 · n n = 27 · [PMID 39408325]
          • Key findings · abstract:Conversely, there was evidence that ingestion of 500 mg of CA increased DHA in plasma, increased neutrophil functionality during the first 8 h of the PK study, promoted increased natural killer cells, and altered weight-adjusted PK profiles, suggesting greater volume distribution and clearance from the blood.
          • Cmax · full text, Section '5.1. Primary Outcomes':The same research group completed a follow-up study with 40 healthy adults who supplemented 1000 mg CA compared to AA and found higher Cmax plasma and leukocyte vitamin C concentrations, though the mean percent change from baseline in plasma vitamin C was similar compared to AA control [1].
          • Cmax · full text, Section '5.1. Primary Outcomes':Interestingly, Purpura and colleagues [8] reported that ingesting 500 mg of a liposomal coated source of L-ascorbic acid promoted a significantly higher Cmax (plasma +27%, leukocytes +20%, and 24 h AUC (plasma +21%, leukocytes +8%) compared to AA.
          • +7 more quotes in Studies
        • HumanBioavailability of calcium in an enriched postbiotic system compared to calcium citrate in healthy postmenopausal females; A randomized, double-blind, comparator-controlled, crossover study.
          Front Nutr, 2023 · n 24 participants · [PMID 37006928]
          • Key findings · abstract:After a 14-h (overnight) fast followed by a single dose of product with a standard low-calcium breakfast, both serum and urine calcium concentrations were assessed for up to 8 and 24 h, respectively.
          • Food effect · abstract:After a 14-h (overnight) fast followed by a single dose of product with a standard low-calcium breakfast, both serum and urine calcium concentrations were assessed for up to 8 and 24 h, respectively.
          • Cmax · full text, Table 2:09) 2.35 (0.08) 2.37 (0.08) iAUC0-8h(mmol/L*h) 0.86 (0.51)a 0.52 (0.45)b 0.60 (0.49)b AUCT0-8h (mmol/L*h) 19.72 (0.74)a 19.34 (0.68)b 19.14 (2.13)a,b Cmax (mmol/L) 2.57 (0.11)a 2.50 (0.10)b 2.54 (0.10)a tmax (h)† 4.0 (2.0–7.0) 4.0 (1.5–8.0) 5.5 (2.0–8.0) Urine Pre-dose urine calcium normalized to creatinine (mmol/mmol) 0.29 (0.19) 0.29 (0.18) 0.30 (0.21) Pre-dose excreted calcium (mg) 5.83 (3.8
          • +10 more quotes in Studies
        • HumanPharmacokinetic/Pharmacodynamic Analysis of Oral Calcium Fosfomycin: Are Urine Levels Sufficient to Ensure Efficacy for Urinary Tract Infections?
          Pharmaceutics, 2023 · [PMID 37111669]
          • Key findings · abstract:The accumulated fraction of fosfomycin excreted in urine was around 18%, consistent with its low oral bioavailability and its almost exclusively renal clearance by glomerular filtration as unchanged drug.
          • Cmax · full text, Table 3:Cmax and Cmax/MIC ratio of urine fosfomycin in the volunteers receiving fosfomycin at different dose levels. Values expressed as mean ± standard deviation. In parenthesis, maximum and minimum values. Cmax(mg/L) Cmax/4 Cmax/8 500 mg single dose 133.72 ±
          • Cmax · full text, Section '3. Results':Table 3 shows the maximum concentration (Cmax) of fosfomycin in the urine samples, as well as the Cmax to MIC ratios for MICs of 4 and 8 mg/L, the tentative epidemiological cut-off (TECOFF) and the clinical breakpoint for E. coli reported by EUCAST, respectively.
          • +7 more quotes in Studies
        • HumanThe Postprandial Calcium Absorption of a Milk-Derived Calcium Permeate - The Acute RENEW Double-Blinded Randomized Controlled Cross-Over Study.
          J Nutr, 2023 · [PMID 37844839]
          • Key findings · abstract:RESULTS: Serum-ionized calcium concentration after the CC supplement was higher at 240 min compared with the CP supplement [between-group difference; 95% confidence interval (CI): 0.039 mmol/L; 95% CI: 0.017-0.061;[excerpt truncated in our database — see source]
          • Key findings · abstract:Serum-ionized calcium concentration after the CC supplement was significantly higher than placebo at all postprandial time points except at 60 min.
          • Key findings · abstract:Urinary calcium concentration in 360 min spot urine was higher after intake of CC compared with CP [between-group difference; 95% CI: 2.47 mmol/L; 95% CI: 1.90-3.03;[excerpt truncated in our database — see source]
          • +2 more quotes in Studies
        • HumanDifferent elemental infant formulas show equivalent phosphorus and calcium bioavailability in healthy volunteers.
          Nutr Res, 2021 · [PMID 33450668]
          • Key findings · abstract:The present study aims to evaluate the bioavailability of phosphorus from 2 commercial elemental formulas and to test our hypothesis of bioequivalence of the 2 products in healthy volunteers receiving gastric acid-suppressive medication.
          • Key findings · abstract:Results show that the geometric mean ratio (GMR) and 90% CI for serum phosphate were 1.041 (0.998-1.086) and 1.020 (0.963-1.080) for AUC0-360 and Cpeak, respectively, meeting the predetermined criteria for bioequivalence.
          • Key findings · abstract:Urinary creatinine-corrected phosphate followed a similar pattern after intake of Product A and B, but did not reach bioequivalence crit[excerpt truncated in our database — see source]
          • +5 more quotes in Studies
        • HumanEffect of various calcium salts on non-heme iron bioavailability in fasted women of childbearing age.
          J Trace Elem Med Biol, 2018 · n 27 women · [PMID 29895376]
          • Key findings · abstract:Iron was labeled with the radioisotopes 59Fe or 55Fe, and the absorption of iron was measured by erythrocyte incorporation of radioactive Fe RESULTS: 800 mg of elemental calcium as calcium citrate produced a significant decrease in non-heme iron bioavailability (repeated measures ANOVA, F = 3.79, p = 0.018).
        • HumanCalcium Bioavailability from Mineral Waters with Different Mineralization in Comparison to Milk and a Supplement.
          J Am Coll Nutr, 2017 · n 21 healthy men · [PMID 28628402]
          • Key findings · abstract:OBJECTIVE: The aim of the present study was to compare the bioavailability of calcium from 3 mineral waters with different concentrations of minerals with that of milk and a calcium supplement.
          • Key findings · abstract:Primary outcome variables were the area under the curve of serum calcium levels for 10-hour (AUC0-10h) and 24-hour urinary calcium excretion.
          • Key findings · abstract:RESULTS: In all groups, no significant differences in the AUC0-10h of serum calcium levels as well as in the 24-hour urinary calcium excretion were observed.
          • +10 more quotes in Studies
        • HumanDietary calcium impairs tomato lycopene bioavailability in healthy humans.
          Br J Nutr, 2016 · [PMID 28069089]
          • Key findings · abstract:Plasma LYC concentration was measured at regular time intervals over 7 h postprandially.
          • Key findings · abstract:LYC bioavailability was diminished by 83 % following the addition of Ca in the test meal.
          • Food effect · abstract:First, in a randomised, two-way cross-over study, ten healthy adults consumed either a test meal that provided 19-mg (all-E)-LYC from tomato paste or the same meal plus 500-mg calcium carbonate as a supplement.
          • +8 more quotes in Studies
        • HumanDietary and pharmacological compounds altering intestinal calcium absorption in humans and animals.
          Nutr Res Rev, 2015 · [PMID 26466525]
          • Relative bioavailability · full text, p.2:erent kinetics. In addition, the tion rate in each intestinal segment. The order of Ca absorption affinity of TRPV5 for the inhibitor ruthenium red is 100-fold that rate is: duodenum > jejunum > ileum(16). Ca absorption in the of TRPV6(32). colon is probably very important in pathological conditions such TRPV6 transcripts have been found in duodenum, but not in as short bowel syndrome(18). ileum, h
          • Relative bioavailability · full text, p.3:of 3 Na+:1 Ca2+ shown in mice that a single administration of 1,25(OH)2D3 and can function in either a forward mode (Ca2+ extrusion) or in produced a 30-fold maximal increase in the ileal TRPV6 mRNA a reversed mode (Ca2+ entry), depending on the Na+ and Ca at 9 h. Multiple dosing of 1,25(OH)2D3 increased the ileal gradients and the membrane potential(63). We have found that TRPV6 to 200- to 600-fo
          • Food effect · full text, p.7:ated to increased intestinal Ca absorption. Meyer et al.(143) via a cation exchange mechanism between cellular H+ for have demonstrated that chickens fed a low-P diet displayed an luminal Ca2+ favoured by exchanger activity 2H+/Ca2+(157). Fatty increase in intestinal VDR mRNA. The authors have reported acids would increase the proliferation of colonic epithelial cells, Nutrition Research Reviews t
          • +5 more quotes in Studies
        • HumanA comparative study of calcium absorption following a single serving administration of calcium carbonate powder versus calcium citrate tablets in healthy premenopausal women.
          Food Nutr Res, 2014 · [PMID 24772062]
          • Key findings · abstract:DESIGN: A two-period, crossover bioavailability study of a single serving of calcium citrate tablets (two tablets=500 mg calcium) versus a single serving of calcium carbonate powder (one packet of powder=1,000 mg calcium) was performed in healthy women aged between 25 and 45.
          • Key findings · abstract:Results showed that administration of a single serving of a calcium carbonate powder resulted in greater absorption in total and ionized calcium versus a single serving of calcium citrate tablets at 4 h (4.25±0.21 vs. 4.16±0.16, p=0.001).
          • Food effect · abstract:All subjects were on a calcium-restricted diet 7 days prior to testing and fasted for 12 h before being evaluated at 0, 1, 2, and 4 h after oral administration of the test agents.
          • +3 more quotes in Studies
        • HumanGalacto-oligosaccharides increase calcium absorption and gut bifidobacteria in young girls: a double-blind cross-over trial.
          Br J Nutr, 2013 · [PMID 23507173]
          • Key findings · abstract:Fractional Ca absorption was determined from urinary Ca excretion over 48 h at the end of each 3-week period using a dual stable isotope method.
          • Key findings · abstract:Fractional Ca absorption after the 48 h treatment with control, 5 and 10 g GOS/d was 0·393 (SD 0·092), 0·444 (SD 0·086) and 0·419 (SD 0·099), respectively.
          • Key findings · abstract:Significant improvements in Ca absorption were seen with both low and high doses of GOS compared with the control (P,0·02), but itwas not a dose-response relationship.
          • +12 more quotes in Studies
        • HumanCalcium absorption response to cholecalciferol supplementation in hemodialysis.
          Clin J Am Soc Nephrol, 2013 · n 30 participants · [PMID 23411428]
          • Key findings · abstract:DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Paired calcium absorption tests were done before and after 12-13 weeks of 20,000 IU weekly cholecalciferol supplementation in 30 participants with stage 5 CKD on hemodialysis.
          • Key findings · abstract:Calcium absorption was tested with a standardized meal containing 300 mg calcium carbonate intrinsically labeled with (45)Ca; 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were measured.
          • Key findings · abstract:The median baseline calcium absorption was 12% (7%-17%) and 12% (7%-16%) at the end of study.
          • +2 more quotes in Studies
        • HumanA randomized, open-label, 5-period, balanced crossover study to evaluate the relative bioavailability of eltrombopag powder for oral suspension (PfOS) and tablet formulations and the effect of a high-calcium meal on eltrombopag pharmacokinetics when administered with or 2 hours before or after PfOS.
          Clin Ther, 2012 · n 11 subjects · [PMID 22336488]
          • Key findings · abstract:Noncompartmental pharmacokinetic parameters were estimated from plasma concentration-time data collected over 72 hours post-dose.
          • Key findings · abstract:Plasma eltrombopag AUC(0-∞) was higher for the PfOS than the tablet (geometric least-squares mean ratio [GMR]: 1.22; 90% CI: 1.08-1.38).
          • Key findings · abstract:Plasma eltrombopag AUC(0-∞) was reduced when the PfOS was administered with a high-calcium meal (GMR: 0.25; 90% CI: 0.224-0.287) or 2 hours after a meal (GMR: 0.53; 90% CI: 0.470-0.601), and, to a lesser extent, when administered 2 hours before a meal (GMR: 0.80; 90% CI: 0.711-0.908).
          • +7 more quotes in Studies
        • HumanPharmacokinetics and pharmacodynamics of calcium-vitamin D(3) chewable tablets: a single-blind, multiple-dose study in postmenopausal women.
          Expert Opin Drug Metab Toxicol, 2011 · [PMID 21635154]
          • Key findings · abstract:OBJECTIVE: The objective of this study is to investigate the effect of a newly developed calcium carbonate-vitamin D₃ chewable tablet formulation (600 mg of calcium + 400 IU of vitamin D₃) on serum/urine calcium and serum parathyroid hormone (PTH) as measures of intestinal calcium absorption compared to a placebo.
          • Key findings · abstract:Total urinary calcium excretion (Ae(0-24 h)) and AUC(0-6 h) for serum calcium were the primary outcome variables and were compared between treatments using a paired sample t-test.
          • Key findings · abstract:RESULTS: Ae(0-24 h) increased by 42% (uncorrected, p = 0.0001) and 30% (creatinine-corrected, p = 0.
          • +4 more quotes in Studies
        • HumanDo proton pump inhibitors decrease calcium absorption?
          J Bone Miner Res, 2010 · [PMID 20578215]
          • Key findings · abstract:Two FCA studies were performed 1 month apart to establish baseline calcium absorption.
          • Key findings · abstract:Multiple linear regression revealed that age, gastric pH, serum omeprazole levels, adherence to omeprazole, and 25-hydroxyvitamin D levels were unrelated to changes in FCA between study visits 2 and 3.
          • Food effect · abstract:Each participant consumed the same foods during all FCA studies; study meals replicated subjects' dietary habits based on 7-day diet diaries.
          • +2 more quotes in Studies
        • HumanMeals and dephytinization affect calcium and zinc absorption in Nigerian children with rickets.
          J Nutr, 2009 · [PMID 19321589]
          • Key findings · abstract:After 6 wk, calcium and zinc absorption were measured in both groups with and without maize porridge using stable isotopes.
          • Key findings · abstract:Calcium absorption was greater with a meal (61.3 +/- 25.1%) than without (27.8 +/- 14.6%;[excerpt truncated in our database — see source]
          • Key findings · abstract:Zinc absorption was lower with a meal (16.2 +/- 8.0%) than without (63.4 +/- 23.9%;[excerpt truncated in our database — see source]
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        • HumanCalcium absorption from commonly consumed vegetables in healthy Thai women.
          J Food Sci, 2008 · [PMID 19021804]
          • Key findings · abstract:The absorbability of calcium from ivy gourd, a green leafy vegetable (Coccinia grandix Voigt.) and winged bean young pods (Psophocarpus tetragonolobus [L] DC) were measured in 19 healthy adult women aged 20 to 45 y, in a 3-way, randomized-order, crossover design with an average calcium load of 100 mg and milk as the referent.
          • Key findings · abstract:Absorption of calcium was determined on a blood sample drawn 5 h after ingestion of the test meal.
          • Key findings · abstract:Fractional calcium absorption (X+/- SD) was 0.391 +/- 0.128 from winged beans, 0.476 +/- 0.109 from ivy gourd, and 0.552 +/- 0.119 from milk.
          • +3 more quotes in Studies
        • HumanAbsorption of zinc and retention of calcium: dose-dependent inhibition by phytate.
          J Trace Elem Med Biol, 2006 · [PMID 16632176]
          • Key findings · abstract:The rolls were labelled extrinsically with radioisotopes, 65Zn and 47Ca, and whole-body retention of both minerals was measured.
          • Key findings · abstract:The zinc absorption in meals to which either 0, 25, 50, 75, 100, 140, 175 or 250 mg of phytate-P (0, 134, 269, 403, 538, 753, 941 or 1344 micromol phytate) had been added was 22%, 16%, 14%, 11%, 7%, 7%, 7% and 6%, respectively (mean values).
          • Key findings · abstract:The addition of 50 mg phytate-P or more significantly decreased zinc absorption (p=0.01) as compared to absorption from the test meals with no added phytate.
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        • HumanRelative bioavailability of calcium from calcium formate, calcium citrate, and calcium carbonate.
          J Pharmacol Exp Ther, 2005 · [PMID 15734899]
          • Key findings · abstract:After calcium carbonate, the maximum rise in serum calcium ( approximately 4%) and the fall in serum intact parathyroid hormone 1-84 (iPTH) (approximately 20-40%) did not differ significantly from placebo.
          • Key findings · abstract:After calcium citrate, the changes were modestly but significantly (p < 0.05) greater, but only at 135 to 270 min after ingestion.
          • Key findings · abstract:In contrast, within 60 min after calcium formate serum calcium rose by approximately 15% and serum iPTH fell by 70%.
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        • HumanCalcium fortification systems differ in bioavailability.
          J Am Diet Assoc, 2005 · [PMID 15883561]
          • Key findings · abstract:The main outcome measure was the area under the curve (AUC) for the increase in serum calcium from 0 to 9 hours after ingesting the test calcium source.
          • Key findings · abstract:AUC 9 was 48% greater for calcium citrate malate than for tricalcium phosphate/calcium lactate ( P < .001); absorbed calcium calculated from AUC 9 values (mean+/-standard error of the mean) was 148+/-9.0 mg and 100+/-8.9 mg for calcium citrate malate and tricalcium phosphate/calcium lactate, respectively.
          • AUC · abstract:The main outcome measure was the area under the curve (AUC) for the increase in serum calcium from 0 to 9 hours after ingesting the test calcium source.
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        • HumanAbsorption of calcium from tortilla meals prepared from low-phytate maize.
          Am J Clin Nutr, 2005 · [PMID 16002804]
          • Key findings · abstract:Isotope ratios of (42)Ca to (43)Ca and of (44)Ca to (43)Ca were measured by inductively coupled plasma mass spectrometry in urine collected as an 8-h pool from the period 16-24 h after intravenous tracer administration and prepared by the oxalate precipitation method.
          • Key findings · abstract:RESULTS: Mean fractional absorption of calcium from tortillas prepared from the low-phytate maize (0.50 +/- 0.03) was significantly (P = 0.003) greater than that from tortillas prepared from the control maize (0.35 +/- 0.07).
          • Fractional absorption · abstract:RESULTS: Mean fractional absorption of calcium from tortillas prepared from the low-phytate maize (0.50 +/- 0.03) was significantly (P = 0.003) greater than that from tortillas prepared from the control maize (0.35 +/- 0.07).
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        • HumanCalcium from milk or calcium-fortified foods does not inhibit nonheme-iron absorption from a whole diet consumed over a 4-d period.
          Am J Clin Nutr, 2004 · n 14 women · [PMID 15277162]
          • Key findings · abstract:OBJECTIVE: We investigated the effect of 3 sources of calcium served with the 3 main meals on nonheme-iron absorption from a 4-d diet.
          • Key findings · abstract:DESIGN: (59)Fe absorption was estimated from whole-body retention measurements in 14 women aged 21-34 y, each of whom consumed four 4-d diets in a randomized crossover design.
          • Key findings · abstract:RESULTS: No significant differences in nonheme-iron absorption were found between the BD and the BD supplemented with milk, calcium lactate, or the milk mineral isolate [7.4% (95% CI: 5.3%, 10.5%), 5.2% (3.5%, 7.9%), 6.7% (5.0%, 8.9%), and 5.1% (3.2%, 7.9%), respectively;[excerpt truncated in our database — see source]
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        • HumanCalcium absorption varies within the reference range for serum 25-hydroxyvitamin D.
          J Am Coll Nutr, 2003 · [PMID 12672710]
          • Key findings · abstract:In the first, in which participants were pretreated with 25-hydroxyvitamin D (25OHD), mean serum 25OHD concentration was 86.5 nmol/L; and in the other, with no pretreatment, mean serum concentration was 50.2 nmol/L.
          • Key findings · abstract:METHODS: Relative calcium absorption at the two 25OHD concentrations was estimated from the area under the curve (AUC) for the load-induced increment in serum total calcium.
          • Key findings · abstract:RESULTS: AUC(9) (+/- SEM), was 3.63 mg hr/dL +/- 0.234 in participants pretreated with 25OHD and 2.20 +/- 0.240 in those not pretreated (P < 0.001).
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        • HumanPhase I and pharmacokinetic study of a micronized formulation of carboxyamidotriazole, a calcium signal transduction inhibitor: toxicity, bioavailability and the effect of food.
          Clin Cancer Res, 2002 · [PMID 11801543]
          • HumanRelative bioavailability of calcium-rich dietary sources in the elderly.
            Am J Clin Nutr, 2002 · n 9 women · [PMID 12450902]
            • Key findings · abstract:OBJECTIVE: We determined the bioavailability of calcium from 3 different sources: orange juice fortified with calcium-citrate malate, skim milk, and a calcium carbonate supplement.
            • Key findings · abstract:This finding suggests that the calcium bioavailability from the 3 sources was equivalent.
            • Key findings · abstract:During the 1-wk high-calcium diet periods, fasting serum calcium increased by 3% (P < 0.0001), serum 1,25-dihydroxyvitamin D decreased by 20% (P < 0.0001), and a biomarker of bone resorption (serum N-telopeptide collagen cross-links) decreased by 14% (P < 0.02) compared with the low-calcium diet period.
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          • HumanInitial uptake and absorption of nonheme iron and absorption of heme iron in humans are unaffected by the addition of calcium as cheese to a meal with high iron bioavailability.
            Am J Clin Nutr, 2002 · n n = 17 · [PMID 12145016]
            • Key findings · abstract:DESIGN: Whole-gut lavage and whole-body scintillation counting methods were applied to determine the 8-h uptake of nonheme iron and the 2-wk retention (absorption) of heme and nonheme iron in healthy adults (n = 17) after the consumption of meals of radiolabeled food.
            • Key findings · abstract:RESULTS: The initial uptake and absorption of nonheme iron were 11% and 7%, respectively, and the absorption of heme iron was 15%.
            • Key findings · abstract:Adding calcium (127 mg in cheese) to the meal did not affect absorption.
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          • HumanCarbonated beverages and urinary calcium excretion.
            Am J Clin Nutr, 2001 · [PMID 11522558]
            • Key findings · abstract:RESULTS: Relative to water, urinary calcium rose significantly only with the milks and the 2 caffeine-containing beverages.
            • Food effect · abstract:Beverages were consumed with a light breakfast after an overnight fast; no other foods were ingested until urine collection was complete. pH, titratable and total acidity, sodium, creatinine, and calcium were measured in 2-h (morning) fasting and 5-h postbeverage urine specimens.
          • HumanPharmacokinetic and pharmacodynamic comparison of two calcium supplements in postmenopausal women.
            J Clin Pharmacol, 2000 · [PMID 11075309]
            • Key findings · abstract:This randomized crossover study compared the single-dose bioavailability and effects on parathyroid function of two commercially formulated calcium supplements containing 500 mg of elemental calcium.
            • Key findings · abstract:Compared with calcium carbonate, calcium citrate provided a 46% greater peak-basal variation and 94% higher change in area under the curve for serum calcium and a 41% greater increment in urinary calcium.
            • AUC · abstract:Compared with calcium carbonate, calcium citrate provided a 46% greater peak-basal variation and 94% higher change in area under the curve for serum calcium and a 41% greater increment in urinary calcium.
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          • HumanThe effect of calcium on iron absorption.
            Nutr Res Rev, 2000 · [PMID 19087437]
            • Fractional absorption · full text, p.6:gether with a hamburger meal. Absorption was reduced by 24% when 300 mg Ca was taken with 37 mg Fe as FeSO4 (P ˆ 0043). With 600 mg Ca and 18 mg Fe, absorption was 44% lower in subjects with reduced Fe stores (P < 0001), but not sig- https://doi.org/10.1079/095442200108729043 Published online by Cambridge University Press
            • Fractional absorption · full text, p.11:er meals that provided most of the dietary Fe, and during the other period the dairy products were provided more evenly throughout the day's diet. Fe absorption was 32% higher when dairy products were eliminated from the main Fe-containing meals. In summary, all but one of the multiple-meal studies indicate that Ca is likely to have a far smaller in¯uence on Fe absorption than would be predicted f
            • Food effect · full text, p.4:eanling rats given large amounts of Ca in their diets (Fuhr & Steenbock, 1943). Young female mice and their litters became anaemic when the dams were fed high doses of CaCO3 (Greig, 1952). Although the majority of experiments carried out in experimental animals have demonstrated an inhibitory effect of Ca, the ®nding has not been universal. Wauben & Atkinson (1999) recently reported that Ca did no
            • +4 more quotes in Studies
          • HumanTransgalactooligosaccharides stimulate calcium absorption in postmenopausal women.
            J Nutr, 2000 · n 12 subjects · [PMID 11110850]
            • Key findings · abstract:Before and during the 36 h after isotope administration, urine was collected and the ratios of isotopes present were measured by inductively coupled plasma mass spectrometry (ICP-MS).
            • Key findings · abstract:TOS increased true calcium absorption 16%, from (mean +/- SD) 20.6 +/- 7.0% during the reference treatment to 23.9 +/- 6.9% during the TOS treatment (P: = 0.04, one-sided).
            • Food effect · abstract:During the treatment periods, 12 subjects drank 200 mL yogurt drink twice (at breakfast and lunch) containing either TOS (20 g/d) or the reference substance, sucrose.
          • HumanRelationship of intestinal calcium absorption to 1,25-dihydroxyvitamin D [1,25(OH)2D] levels in young versus elderly women: evidence for age-related intestinal resistance to 1,25(OH)2D action.
            J Clin Endocrinol Metab, 2000 · n n = 20 · [PMID 11095427]
            • Key findings · abstract:Intestinal calcium absorption decreases with aging, but it is unclear whether this is attributable to an age-related intestinal resistance to 1,25-dihydroxyvitamin D [1,25(OH)2D] action.
            • Key findings · abstract:Thus, we assessed the in vivo dose response of active intestinal calcium absorption to a broad range of circulating 1,25(OH)2D levels in elderly [age (mean +/- SD), 72.5+/-3.0 yr] vs. young women (age, 28.7+/-5.3 yr; n = 20 per group), who were stratified into 5 subgroups: group 1 was given a high calcium intake of 75 mmol/day, suppressing 1,25(OH)2D levels; group 2 was given a normal calcium diet of 15-30 m[excerpt truncated in our database — see source]
            • Food effect · abstract:After 7 days of diet and/or 1,25(OH)2D treatment, fasting fractional calcium absorption (FCA) was assessed by a double-tracer method using stable calcium isotopes.
          • HumanPharmacokinetics of calcium absorption from two commercial calcium supplements.
            J Clin Pharmacol, 1999 · [PMID 10579145]
            • Key findings · abstract:This study was conducted to compare pharmacokinetic indices of calcium absorption after a single oral (500 mg calcium) load of Citracal (calcium citrate) and Os-Cal (calcium carbonate).
            • Key findings · abstract:The change in area under the curve (delta AUC) in serum calcium from preload was 2.5-fold greater for Citracal than Os-Cal, and the peak-basal variation in serum calcium was 76% higher for Citracal than Os-Cal.
            • Key findings · abstract:The increment in serum calcium from preload after Citracal administration was significantly higher than that obtained after placebo load during most time periods and significantly higher than that of[excerpt truncated in our database — see source]
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          • HumanCalcium bioavailability and parathyroid hormone acute changes after oral intake of dairy and nondairy products in healthy volunteers.
            Osteoporos Int, 1999 · [PMID 10501794]
            • Key findings · abstract:This study was designed to compare calcium bioavailability and serum parathyroid hormone acute changes after oral intake of 500 mg of elemental calcium from liquid milk, yogurt, calcium-citrate-enriched powdered milk or a calcium carbonate pill; or after intake of soybean imitation-milk.
            • Key findings · abstract:Calcium-citrate-enriched powdered milk induced a significant increase in serum ionized calcium (p<0.001) and a significant and continuous decrease in serum iPTH concentration (p<0. 001).
            • Key findings · abstract:Yogurt and the calcium carbonate pill induced a similar but less significant effect, increasing serum ionized calcium (p[excerpt truncated in our database — see source]
            • +1 more quotes in Studies
          • HumanLactulose stimulates calcium absorption in postmenopausal women.
            J Bone Miner Res, 1999 · [PMID 10404023]
            • Key findings · abstract:Based on isotope ratios measured in urine collected before and until 36 h after isotope administration, true fractional calcium absorption was calculated.
            • Key findings · abstract:Calcium absorption during the treatments with the reference substance, 5 g and 10 g of lactulose was (mean +/- SD) 27.7 +/- 7.7, 30.0 +/- 7.6, and 32.2 +/- 7.0, respectively.
            • Key findings · abstract:A significant difference in calcium absorption was found between the highest dose of lactulose and the reference treatment (p < 0.01).
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          • HumanEffect of dietary calcium on urinary oxalate excretion after oxalate loads.
            Am J Clin Nutr, 1997 · [PMID 9129476]
            • Key findings · abstract:Mean 24-h oxalate absorption decreased significantly from that at the time of the baseline treatment (18.3%) after both calcium carbonate (8.1%) and CCM (7.2%) treatments.
            • Key findings · abstract:In R-2, mean 24-h oxalate absorption was significantly lower after 200 (5.9%) and 300 (7.6%) mg Ca than after 100 mg Ca (9.1%) and the OL alone (11.3%).
            • Key findings · abstract:Concomitant meal ingestion significantly decreased oxalate absorption in the absence of dietary calcium but not in association with the 300-mg Ca treatment.
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          • HumanPostprandial parathyroid hormone response to four calcium-rich foodstuffs.
            Am J Clin Nutr, 1997 · [PMID 9174467]
            • Key findings · abstract:The serum ionized calcium concentration increased significantly after ingesting cheese (P = 0.004, contrast analysis) or calcium salt (P = 0.05, contrast analysis) compared with the control session.
            • Key findings · abstract:Compared with the control session, the serum phosphate concentration increased after the cheese session (P = 0.004, contrast analysis) and after the milk session (P = 0.02, contrast analysis).
            • Key findings · abstract:Calcium salt (P = 0.007, contrast analysis) and cheese (P = 0.002, contrast analysis) caused a significant decline in serum intact parathyroid hormone compared with the control session.
            • +2 more quotes in Studies
          • HumanCalcium bioavailability from bovine milk and dairy products in premenopausal women using intrinsic and extrinsic labeling techniques.
            J Nutr, 1996 · [PMID 8618137]
            • Key findings · abstract:Healthy Caucasian women were fed a controlled diet for 4 d during the follicular phase of their menstrual cycle.
            • Key findings · abstract:Fractional absorption was determined as the difference between the administered isotopic dose and the quantity of 44Ca or 42Ca excreted in feces.
            • Fractional absorption · abstract:Fractional absorption was determined as the difference between the administered isotopic dose and the quantity of 44Ca or 42Ca excreted in feces.
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          • HumanEffect of gastric acid secretion on intestinal phosphate and calcium absorption in normal subjects.
            Nephrol Dial Transplant, 1995 · [PMID 8538929]
            • Key findings · abstract:In eight normal subjects we measured 24-h urinary calcium phosphate excretion and the postprandial blood calcium phosphate profile after a meal containing 1 g of calcium and 2 g of phosphate salts in a crossover placebo-omeprazole study.
            • Key findings · abstract:RESULTS: Serum gastrin levels were measured as an indicator of achlorhydria and were 13.7 +/- 1 pg/ml after placebo and 30.4 +/- 4.7 after omeprazole (P < 0.003).
            • Key findings · abstract:Postprandial plasma phosphate profiles were not significantly different between the two studies (+36 +/- 8% after placebo and +24 +/- 8% after omeprazole, NS), while plasma calcium increased by +[excerpt truncated in our database — see source]
            • +2 more quotes in Studies
          • HumanHypochlorhydria from short-term omeprazole treatment does not inhibit intestinal absorption of calcium, phosphorus, magnesium or zinc from food in humans.
            J Am Coll Nutr, 1995 · n n = 5 · [PMID 8568113]
            • Key findings · abstract:Mineral absorption was measured twice in each subject, once with 120 mL of 0.1 mol/liter hydrochloric acid and a second time with 120 mL of distilled water alone.
            • Food effect · abstract:Omeprazole treatment of normal volunteers resulted in a significant change in postprandial gastric pH (pH 6.4 +/- 0.3 vs. 3.6 +/- 0.5 in control subjects, p < 0.01) and baseline fasting pH (pH 5.8 +/- 0.5 vs. pH 1.8 +/- 0.3 in controls, p < 0.01) after an overnight fast.
          • HumanTrue fractional calcium absorption in Chinese children measured with stable isotopes (42Ca and 44Ca).
            Br J Nutr, 1994 · [PMID 7827009]
            • Key findings · abstract:TFCA of a lower-Ca-intake group (Ca < or = 500 mg/d, n19) with mean Ca intake 359 mg/d was 63.1 (SD 10.7)% and that of a higher-Ca-intake group (Ca > 500 mg/d, n15) with mean Ca intake 862 mg/d was 54.8 (SD 7.3)%; the difference in TFCA was significant (P = 0.016).
            • Key findings · abstract:Serum levels of 25-hydroxycholecalciferol of the children were adequate (33.7 (SD 7.7) ng/ml).
            • Key findings · abstract:If it is assumed that dietary Ca absorption by Chinese children resembles their TFCA from a single meal of chocolate milk, then the recommended dietary allowance (RDA) for Ca for Chinese children would be lower than the US RDA (800 mg/[excerpt truncated in our database — see source]
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          • HumanShort-term dietary calcium fortification increases fecal saturated fat content and reduces serum lipids in men.
            J Nutr, 1993 · n 13 healthy men · [PMID 8505664]
            • Key findings · abstract:The effect of dietary calcium on fecal fatty acid excretion and serum lipids was tested in a randomized, single-blind metabolic study in 13 healthy men with moderate hypercholesterolemia.
            • Key findings · abstract:The percentage of dietary saturated fat excreted per day increased from 6 to 13% with calcium fortification.
            • Key findings · abstract:Urinary calcium excretion increased from 146 to 230 mg/d when the high Ca diet was consumed.
            • +1 more quotes in Studies
          • HumanNet calcium absorption in premature infants: results of 103 metabolic balance studies.
            Am J Clin Nutr, 1992 · n 103 infants · [PMID 1307704]
            • Key findings · abstract:Net calcium absorption was evaluated in 103 low-birth-weight preterm infants by a 72-h balance technique.
            • Key findings · abstract:When tested 3 wk later, their net calcium absorption averaged 58 +/- 1% with an intake of 80 +/- 2 mg Ca.kg body wt-1.d-1.
            • Key findings · abstract:Net calcium absorption was a linear function of intake (40-130 mg Ca.kg body wt-1.d-1) with a zero intercept.
            • +1 more quotes in Studies
          • HumanCalcium and iron absorption: mechanism of action and nutritional importance.
            Eur J Clin Nutr, 1992 · [PMID 1600930]
            • Key findings · abstract:We investigated the inhibitory effect of calcium on iron absorption in 57 human subjects.
            • Key findings · abstract:No inhibiting effect on iron absorption was seen when adding 3 mg calcium to 0.01 mg iron (molar ratio Ca/Fe = 420).
            • Key findings · abstract:The practical nutritional implications of the inhibitory effect of calcium are considerable since addition of milk, milkshake or cheese to common meals such as pizza or hamburger meals reduced iron absorption by 50-60%.
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          • HumanHuman calcium absorption from whole-wheat products.
            J Nutr, 1991 · [PMID 1941185]
            • Key findings · abstract:In the first study, fractional calcium absorption from leavened whole-wheat bread averaged 0.817 +/- 0.124.
            • Key findings · abstract:By comparison, absorption from milk, ingested at a comparable load in the same women, averaged only 0.589 +/- 0.111.
            • Key findings · abstract:When labeled bread was co-ingested with milk, at the same aggregate load as for bread alone, bread calcium absorption fell to 0.748 +/- 0.103 (P less than 0.05).
            • +3 more quotes in Studies
          • HumanCalcium bioavailability from calcium fortified food products.
            J Nutr Sci Vitaminol (Tokyo), 1991 · [PMID 1765836]
            • Food effect · full text, p.4:um-fortified food products under study (orange juice OJ, milk M, soda S, and experimental cheese T) or a calcium carbonate plus vitamin D tablet (CC) with breakfast. The calcium sources used to fortify these food products were different. For example: S contained CaCO3+Ca gluconate , T contained Ca3PO4, OJ contained Ca citrate malate and the milk contained CaCO3. Supplemented calcium in experimenta
            • Food effect · full text, p.9:um salts. N. Engl. J. Med., 317, 532-536. 13) Greger, J. L., Krzykowski, C. E., Khazen, R. R., and Krashol, C. L. (1987): Mineral utilization by rats fed various commercially available calcium supplements or milk. J. Nutr., 117, 717-724. 14) Recker, R. R., Bammi, A., Barger-Lux, M. J., and Heaney, P. R. (1988): Calcium absorbability from milk products, an imitation milk and calcium carbonate. Am.
            • Form comparison · full text, p.4:um excretions were not found to be statistically significantly different, but fecal calcium tended to be lower when subjects consumed M, OJ, and S as compared to control, CC, and T (39 .4. 550, and 43.2% versus 50.1, 54.4, and 55.5%, respectively) . A few recently-published studies reported that the form of calcium in the orange juice used in this experiment J. Nutr, Sci. Vitaminol.
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          • HumanCalcium supplementation: effect on iron absorption.
            Am J Clin Nutr, 1991 · [PMID 1984334]
            • Key findings · abstract:The influence of calcium supplements on the absorption of dietary nonheme iron and of iron supplements was evaluated in 61 normal volunteer subjects by use of a double-radioisotope technique.
            • Key findings · abstract:When taken without food, calcium carbonate did not inhibit the absorption of ferrous sulphate with doses of either 300 mg Ca and 37 mg Fe or 600 mg Ca and 18 mg Fe.
            • Key findings · abstract:However, at the latter levels, calcium citrate and calcium phosphate reduced iron absorption significantly by 49% and 62%, respectively.
            • +1 more quotes in Studies
          • HumanCalcium absorption in elderly subjects on high- and low-fiber diets: effect of gastric acidity.
            Am J Clin Nutr, 1991 · [PMID 1852094]
            • Key findings · abstract:In control subjects calcium retention, measured in a whole-body counter, was 25.7 +/- 4.0% (mean +/- SD) with the low-fiber meal, 19.1 +/- 1.9% with the high-fiber meal (P less than 0.002 vs low fiber), and 18.9 +/- 3.3% with the high-fiber-plus-acid meal (P less than 0.002 vs low fiber, NS vs high fiber).
            • Key findings · abstract:Calcium absorption in achlorhydric subjects was not different from control subjects: 26.2 +/- 8.0% with low fiber, 19.6 +/- 4.1% with high fiber (P less than 0.04 vs low fiber), and 21.0 +/- 5.8% with high fiber plus acid (P less than 0.04 vs low fiber, NS vs high fiber).
            • Food effect · abstract:In nine normal, elderly control subjects and eight elderly subjects with achlorhydria, 47Ca was ingested with three test meals: a low-fiber meal (0.5 g dietary fiber), a high-fiber meal (10.5 g), and a high-fiber meal with 120 mL of 0.1 mol HC/L.
            • +1 more quotes in Studies
          • HumanFluoride bioavailability from slow-release sodium fluoride given with calcium citrate.
            J Bone Miner Res, 1990 · [PMID 2239370]
            • Key findings · abstract:Following a single oral administration of 50 mg slow-release sodium fluoride, a peak serum fluoride concentration (Cmax) of 184 ng/ml was reached in 2 h; thereafter, serum fluoride concentration declined with a T1/2 of 5.9 h.
            • Key findings · abstract:The concurrent administration of calcium citrate (400 mg calcium) gave an equivalent Tmax (time required to attain Cmax) and T1/2, but a lower Cmax of 135 ng/ml.
            • Key findings · abstract:The area under the serum concentration curve of slow-release sodium fluoride was reduced 17-27% by a meal or calcium citrate.
            • +6 more quotes in Studies
          • HumanEffects of different calcium sources on iron absorption in postmenopausal women.
            Am J Clin Nutr, 1990 · [PMID 2296934]
            • Key findings · abstract:We measured the effect of calcium from food and supplement sources on whole-body retention of 59Fe in 19 normal postmenopausal women.
            • Key findings · abstract:Retention of 59Fe was 8.3 +/- 1.1% (means +/- SEM) with placebo, 3.4 +/- 0.78% with milk, 6.0 +/- 0.97% with CCM, and 7.4 +/- 1.7% with CCM plus orange juice.
            • Key findings · abstract:When compared with placebo, milk and CCM significantly lowered iron retention (p less than 0.05) whereas CCM plus orange juice did not.
            • +5 more quotes in Studies
          • HumanCalcium supplementation lowers serum parathyroid hormone levels in elderly subjects.
            J Gerontol, 1990 · n 40 healthy volunteers · [PMID 2203847]
            • Key findings · abstract:Calcium supplementation (1000 mg/day) decreased serum PTH levels from a mean of 50.1 +/- 3.0 pg/ml to 41.9 +/- 2.4 pg/ml (p less than .001).
            • Key findings · abstract:Additionally, urine calcium excretion significantly increased during calcium administration (from 3.64 mmol/mmol creatinine at baseline to 4.28 mmol/mmol creatinine), but creatinine clearances and serum calcium levels remained unchanged.
            • Food effect · abstract:Fasting blood samples and 24-hour urine collections were obtained at baseline, and at the end of each intervention period.
          • HumanInfluence of calcium load on absorption fraction.
            J Bone Miner Res, 1990 · [PMID 2270776]
            • Key findings · abstract:True calcium absorption was studied as a function of the size of the ingested load in healthy adult women, under meal conditions and at loads ranging from 15 to 500 mg calcium.
            • Key findings · abstract:Fractional absorption was highly inversely correlated with the logarithm of load (P less than 0.001).
            • Key findings · abstract:At the lowest loads, absorption averaged 64.0% and at the highest, 28.6%.
            • +2 more quotes in Studies
          • HumanCalcium absorption in children estimated from single and double stable calcium isotope techniques.
            Clin Chim Acta, 1989 · [PMID 2791301]
            • Key findings · abstract:High-resolution, fast atom bombardment mass spectrometry was used to quantify the 44Ca and 42Ca tracers in serum and urine.
            • Key findings · abstract:The average calcium absorption estimated from the ratio of urinary tracers was 41.4 +/- 8.2%.
            • Key findings · abstract:This study indicates that the level of oral tracer in serum taken 150 min post-ingestion is significantly correlated (r = 0.85, p less than 0.05) with calcium absorption, as determined by the tracer levels in the urine.
            • +1 more quotes in Studies
          • HumanOxalate: effect on calcium absorbability.
            Am J Clin Nutr, 1989 · [PMID 2801588]
            • Key findings · abstract:Absorption of calcium from intrinsically labeled Ca oxalate was measured in 18 normal women and compared with absorption of Ca from milk in these same subjects, both when the test substances were ingested in separate meals and when ingested together.
            • Key findings · abstract:Fractional Ca absorption from oxalate averaged 0.100 +/- 0.043 when ingested alone and 0.140 +/- 0.063 when ingested together with milk.
            • Key findings · abstract:Absorption was, as expected, substantially lower than absorption from milk (0.358 +/- 0.113).
            • +1 more quotes in Studies
          • HumanCalcium absorbability from spinach.
            Am J Clin Nutr, 1988 · n 13 healthy adults · [PMID 3354496]
            • Key findings · abstract:The absorbability of calcium from spinach was compared with the absorbability of Ca from milk in 13 healthy adults in a randomized cross-over design in which the test meal of either milk or spinach had 200 mg of Ca labeled with 45Ca.
            • Key findings · abstract:Absorption was higher from milk in every case, with the mean absorption from milk averaging 27.6% and from spinach, 5.1%.
            • Key findings · abstract:The mean within-subject difference between Ca absorption from milk and from spinach was 22.5 +/- 9.5% (P less than 0.0001).
            • +1 more quotes in Studies
          • HumanVariability of calcium absorption.
            Am J Clin Nutr, 1988 · n 22 subjects · [PMID 3341257]
            • Key findings · abstract:Variability in calcium absorption was estimated in three groups of normal subjects in whom Ca absorption was measured by standard isotopic-tracer methods at interstudy intervals ranging from 1 to 4 mo.
            • Key findings · abstract:Fifty absorption tests were performed in 22 subjects.
            • Key findings · abstract:The coefficient of variation (CVs) for absorption for the three groups ranged from 10.57 to 12.79% with the size of the CV increasing with interstudy duration.
            • +3 more quotes in Studies
          • HumanCalcium absorption: effect of meal and glucose polymer.
            Am J Clin Nutr, 1988 · [PMID 3407610]
            • Key findings · abstract:Using a single-day method, we measured net Ca absorption from Ca carbonate when ingested in fasting state, with a steak and potatoes meal, and with the meal and 50 g glucose polymer.
            • Key findings · abstract:Mean net Ca absorption was 195 +/- 18 mg (4.87 +/- 0.45 mmol) fasting, 213 +/- 21 mg (5.31 +/- 0.52 mmol) with a meal, and 179 +/- 16 mg (4.47 +/- 0.40 mmol) with a meal plus glucose polymer.
            • Key findings · abstract:In normal people Ca absorption from Ca carbonate was not significantly enhanced by a meal or by 50 g glucose polymer ingested with food.
            • +3 more quotes in Studies
          • HumanGastrointestinal absorption of calcium from milk and calcium salts.
            N Engl J Med, 1987 · [PMID 3614304]
            • Key findings · abstract:Using a method by which the net absorption of calcium can be accurately measured after a single dose, we studied eight healthy fasting subjects after they took a 500-mg dose of calcium from each of five calcium salts with various degrees of water solubility and from milk.
            • Key findings · abstract:The mean (+/- SEM) net calcium absorption, in decreasing order of the solubility of the salts, was 32 +/- 4 percent from calcium acetate, 32 +/- 4 percent from calcium lactate, 27 +/- 3 percent from calcium gluconate, 30 +/- 3 percent from calcium citrate, and 39 +/- 3 percent from calcium carbonate.
            • Key findings · abstract:Calcium absorption fr[excerpt truncated in our database — see source]
            • +1 more quotes in Studies
          • HumanCalcium bioavailability from calcium carbonate and calcium citrate.
            J Clin Endocrinol Metab, 1985 · [PMID 4008614]
            • Key findings · abstract:The urinary calcium following calcium citrate load significantly higher (by 20-66%), whether expressed as the total amount or as the increment above basal (fasting) excretion.
            • Food effect · abstract:The urinary calcium following calcium citrate load significantly higher (by 20-66%), whether expressed as the total amount or as the increment above basal (fasting) excretion.
          • HumanCalcium absorption and achlorhydria.
            N Engl J Med, 1985 · [PMID 4000241]
            • Key findings · abstract:I compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects.
            • Key findings · abstract:Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier.
            • Key findings · abstract:Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001).
            • +2 more quotes in Studies
          • HumanEstimation of true calcium absorption.
            Ann Intern Med, 1985 · [PMID 4037557]
            • Key findings · abstract:True absorption, body size, and miscible pool turnover could together explain better than 93% of the variance in serum calcium specific activity values 5 hours after a tracer-labeled test meal.
            • Key findings · abstract:Because measurement of pool turnover is not available routinely, it was dropped from the model, and a predictor equation was developed that allowed estimation of true absorption from the 5-hour serum specific activity value, height, and weight.
            • Key findings · abstract:These variables explained 90.8% of the variance in the 5-hour values and gave estimates of true absorption with a 95% confidence interval of +/- 0.055.
            • +1 more quotes in Studies
          • HumanEffect of phosphate supplementation to breast fed very low birthweight infants on urinary calcium excretion, serum immunoreactive parathyroid hormone and plasma 1,25-dihydroxy-vitamin D concentration.
            Acta Paediatr Scand, 1985 · [PMID 3840317]
            • Key findings · abstract:The concentration of calcium and phosphorus in serum and urine, the serum concentration of immunoreactive parathyroid hormone (iPTH) and the plasma 1,25-dihydroxy-vitamin D concentration (1,25-OH-D) were compared to the values in 19 control infants.
            • Key findings · abstract:The mean +/- SD concentrations in control infants and adults are 63 +/- 18 microliters Eq/ml for serum iPTH and 85 +/- pmol/l for plasma 1,25-OH-D.
            • Key findings · abstract:With 0.48 P supplementation, urinary Ca (UCa) excretion (median and range) 0.238 mmol/kg/24 h (0.105-0.520) was lower than in the control group 0.288 (0.205-0.679) (p less than 0.05); the reduction[excerpt truncated in our database — see source]
            • +1 more quotes in Studies
          • RodentBone composition and histology of young growing rats fed diets of varied calcium bioavailability: spinach, nonfat dry milk, or calcium carbonate added to casein.
            J Nutr, 1992 · [PMID 1729463]
            • Key findings · abstract:In contrast, when calcium is fed to growing animals at levels below the National Research Council requirement but from a highly bioavailable source (i.e., NFDM and CaCO3), there is only a reduction in bone quantity.
            • Food effect · abstract:Bone composition and histology were evaluated in young growing rats fed nutritionally complete but calcium-restricted (0.15%) diets in which calcium was derived from spinach, nonfat dry milk (NFDM), or CaCO3 added to casein.
            • Food effect · abstract:Groups of male weanling rats were pair-fed for 28 d.
            • +2 more quotes in Studies

          Best time to take Calcium

          Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.human data · drafthow we gradeSpecies (abstract screen): 4 human

          Grade basis (abstract screen): 3 human randomized/crossover studies; A-eligible only once the reviewer confirms they agree (capped at B until then). Auto-computed draft grade — pending reviewer review.

          Show 4 studies with verbatim quotes
          • HumanComparative Effectiveness of Ascorbic Acid vs. Calcium Ascorbate Ingestion on Pharmacokinetic Profiles and Immune Biomarkers in Healthy Adults: A Preliminary Study.
            Nutrients, 2024 · n n = 27 · [PMID 39408325]
            • Key findings · abstract:Conversely, there was evidence that ingestion of 500 mg of CA increased DHA in plasma, increased neutrophil functionality during the first 8 h of the PK study, promoted increased natural killer cells, and altered weight-adjusted PK profiles, suggesting greater volume distribution and clearance from the blood.
            • Cmax · full text, Section '5.1. Primary Outcomes':The same research group completed a follow-up study with 40 healthy adults who supplemented 1000 mg CA compared to AA and found higher Cmax plasma and leukocyte vitamin C concentrations, though the mean percent change from baseline in plasma vitamin C was similar compared to AA control [1].
            • Cmax · full text, Section '5.1. Primary Outcomes':Interestingly, Purpura and colleagues [8] reported that ingesting 500 mg of a liposomal coated source of L-ascorbic acid promoted a significantly higher Cmax (plasma +27%, leukocytes +20%, and 24 h AUC (plasma +21%, leukocytes +8%) compared to AA.
            • +7 more quotes in Studies
          • HumanGalacto-oligosaccharides increase calcium absorption and gut bifidobacteria in young girls: a double-blind cross-over trial.
            Br J Nutr, 2013 · [PMID 23507173]
            • Key findings · abstract:Fractional Ca absorption was determined from urinary Ca excretion over 48 h at the end of each 3-week period using a dual stable isotope method.
            • Key findings · abstract:Fractional Ca absorption after the 48 h treatment with control, 5 and 10 g GOS/d was 0·393 (SD 0·092), 0·444 (SD 0·086) and 0·419 (SD 0·099), respectively.
            • Key findings · abstract:Significant improvements in Ca absorption were seen with both low and high doses of GOS compared with the control (P,0·02), but itwas not a dose-response relationship.
            • +12 more quotes in Studies
          • HumanCarbonated beverages and urinary calcium excretion.
            Am J Clin Nutr, 2001 · [PMID 11522558]
            • Key findings · abstract:RESULTS: Relative to water, urinary calcium rose significantly only with the milks and the 2 caffeine-containing beverages.
            • Food effect · abstract:Beverages were consumed with a light breakfast after an overnight fast; no other foods were ingested until urine collection was complete. pH, titratable and total acidity, sodium, creatinine, and calcium were measured in 2-h (morning) fasting and 5-h postbeverage urine specimens.
          • HumanVariability of calcium absorption.
            Am J Clin Nutr, 1988 · n 22 subjects · [PMID 3341257]
            • Key findings · abstract:Variability in calcium absorption was estimated in three groups of normal subjects in whom Ca absorption was measured by standard isotopic-tracer methods at interstudy intervals ranging from 1 to 4 mo.
            • Key findings · abstract:Fifty absorption tests were performed in 22 subjects.
            • Key findings · abstract:The coefficient of variation (CVs) for absorption for the three groups ranged from 10.57 to 12.79% with the size of the CV increasing with interstudy duration.
            • +3 more quotes in Studies

          Calcium cost per mg calculator

          Educational information about published research; not medical advice. Not intended to diagnose, treat, cure or prevent any disease. Talk to a clinician before changing supplements, especially if pregnant, nursing or on medication.

          Enter what you pay. We calculate cost per mg, and cost per mg absorbed only as a range and only where a cited, reviewer-verified absorption range exists for that form.

          Cost per mg (from your label): —

          Cost per mg absorbed: not available for this form yet. No reviewer-verified, cited absorption range is in our database, and we won't estimate one.

          This tool compares prices using published ranges. It does not estimate how much you personally absorb and does not recommend a dose. Absorption varies with the person, the dose, food and the product. Not medical advice.

          FAQ

          Is Calcium citrate better absorbed than carbonate?

          Citrate measured higher than carbonate in 7 of 12 human head-to-head studies we have (grade C, draft). See section →

          Should Calcium be taken with food?

          We have 64 relevant studies in our database that mention food or fasting. See section →

          When is the best time to take Calcium?

          We have 4 relevant studies in our database that mention timing. See section →

          Is this dosing advice?

          No. We summarize published absorption research and compare prices. Talk to a clinician about what's right for you. See section →

          Answers summarize the data on this page; drafts pending reviewer sign-off.

          Evidence grades

          Rubric v2: single-form human studies count. Hover or focus a grade for what it means; see the methodology. All grades are drafts pending reviewer sign-off.

          QuestionGrade & basisSpecies
          Page grade (best of the grades below)Grade AA: well characterized in people. Forms: 5+ human studies, 100+ participants, randomized/crossover designs, consistent values. Comparisons: agreeing head-to-head and matched single-form evidence with clear separation. All grades are drafts pending reviewer sign-off.rubric v2, draft
          Carbonate: absorption evidenceGrade AA: well characterized in people. Forms: 5+ human studies, 100+ participants, randomized/crossover designs, consistent values. Comparisons: agreeing head-to-head and matched single-form evidence with clear separation. All grades are drafts pending reviewer sign-off.
          16 human studies, total n=369, 15 randomized/crossover; median CV 63.400000000000006% across 2 matched set(s) (consistent)
          		human
          Citrate: absorption evidenceGrade AA: well characterized in people. Forms: 5+ human studies, 100+ participants, randomized/crossover designs, consistent values. Comparisons: agreeing head-to-head and matched single-form evidence with clear separation. All grades are drafts pending reviewer sign-off.
          8 human studies, total n=266, 8 randomized/crossover; median CV 63.0% across 2 matched set(s) (consistent)
          		human
          Citrate malate: absorption evidenceGrade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.
          3 human studies, total n=30, 2 randomized/crossover; consistency not evaluable (no matched set with ≥2 studies)
          		human
          Citrate vs CarbonateGrade CC: limited or conflicting human data: 1–2 studies, head-to-head and single-form evidence disagree, or baseline correction not reported. All grades are drafts pending reviewer sign-off.
          head-to-head only; no matched single-form separation. H2H: C (12 human studies (12 randomized/crossover); majority: first form higher (7 agree, 4 contradict)); indirect: none
          		human (head-to-head + matched single-form)
          With food (abstract screen)Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.human + animal data · drafthow we grade
          29 human randomized/crossover studies; A-eligible only once the reviewer confirms they agree (capped at B until then). Auto-computed draft grade — pending reviewer review.
          		63 human, 1 rodent
          Best time (abstract screen)Grade BB: solid human data. Forms: 3+ human studies. Comparisons: one randomized head-to-head, or matched single-form evidence from 2+ studies per form. All grades are drafts pending reviewer sign-off.human data · drafthow we grade
          3 human randomized/crossover studies; A-eligible only once the reviewer confirms they agree (capped at B until then). Auto-computed draft grade — pending reviewer review.
          		4 human

          Studies (186)

          Sorted human → primate → pig → rodent → other animal → in vitro. Quotes are verbatim from the abstract or free full text. Paywalled papers: abstract only.

          Show all 186 studies and quotes
          1. HumanOral calcium supplements to reduce the bioaccessibility and bioavailability of arsenic and lead in contaminated soil.
            Sci Rep, 2026 · Design: not stated · abstract only (PubMed) · not checked (off-topic)
            PMID 41896312DOI 10.1038/s41598-026-44078-3PMC13039500 (free full text)
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:More importantly, the Ca acetate (~ 200 mg Ca kg-1) was the most effective in reducing relative bioavailability of As and Pb based on mouse bioassay.
            • Relative bioavailability · abstract:More importantly, the Ca acetate (~ 200 mg Ca kg-1) was the most effective in reducing relative bioavailability of As and Pb based on mouse bioassay.
          2. HumanDigested casein-stabilized co-dissolution of calcium and iron in oxalate system for enhanced metal bioavailability.
            Colloids Surf B Biointerfaces, 2026 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 42508282DOI 10.1016/j.colsurfb.2026.116015
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:Thermodynamic analysis revealed that iron(II) oxalate exhibited higher solubility product (Ksp) and weaker association (Ka = 4655) compared to calcium oxalate (Ka = 25126) at 25 ℃.
            • Key findings · abstract:Critically, Caco-2 cell studies demonstrated that digested casein-mediated nanoparticles restored both calcium and iron absorption despite oxalate presence, operating primarily through caveolin-mediated endocytosis rather than classical mineral transporters.
          3. HumanTailored saturated phosphatidylcholine liposomes enhance the physicochemical stability and intestinal bioavailability of ascorbic acid and calcium ascorbate.
            Food Chem, 2026 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 42289143DOI 10.1016/j.foodchem.2026.149827
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:Caco-2 cell assays confirmed enhanced intracellular uptake and transepithelial transport, particularly for Liposomal-CA.
          4. HumanConstruction of a xanthan gum-sodium carboxymethylcellulose hydrogel for enhanced gastrointestinal stability and in vivo calcium bioavailability of Mytilus edulis-derived peptide-calcium complex.
            J Sci Food Agric, 2026 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 42046278DOI 10.1002/jsfa.70678
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:CONCLUSION: The results indicate that the development of the hydrogel system addresses key issues such as poor stability and low bioavailability of peptide-calcium chelates in the gastrointestinal environment, providing an innovative solution to enhance their calcium absorption efficacy. © 2026 Society of Chemical Industry.
          5. HumanMoringa oleifera Lam. Leaf Peptide-Calcium Chelate (KTFQGPPHG-Ca): Screening, In Vitro Digestive Stability, Cellular Transport, and Potential Calcium Absorption Mechanisms.
            J Agric Food Chem, 2026 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 42690773DOI 10.1021/acs.jafc.6c04863
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:During simulated digestion, KTFQGPPHG-Ca showed high intestinal-phase stability, with a calcium retention rate of 94.13 ± 1.47%, while its major digestive fragment, TFQGPPHG, retained substantial calcium-binding activity.
            • Key findings · abstract:Proteomic analysis suggested that these chelates may regulate calcium absorption-associated epithelial pathways, including "cell adhesion molecules" and "ECM-receptor interaction," which may contribute to epithelial barrier integrity and cell-matrix signaling associated with Ca2+ transport.
          6. HumanThe chelation mechanism, stability and calcium absorption activity of Ruditapes philippinarum peptide‑calcium chelate.
            Food Chem, 2026 · Design: not stated · abstract only (PubMed) · closed/paywalled
            PMID 42258944DOI 10.1016/j.foodchem.2026.149794
            Verification: abstract-only auto-extract; unverified
            • Key findings · abstract:RPP-Ca demonstrated high stability, maintaining an 80%-85% calcium retention rate at pH 6.0-10.0.
            • Key findings · abstract:Furthermore, calcium transport assays showed that RPP-Ca's transport capacity was 42.20 ± 1.54% higher than that of inorganic CaCl2.
          7. HumanFatty acid distribution in human milk triacylglycerols regulates lipid absorption through calcium-mediated mucus phase transition.
            Food Chem, 2026 · Design: not stated · abstract only (PubMed) · open access (green)
            PMID 41610769DOI 10.1016/j.foodchem.2026.148171
            Verification: abstract-only auto-extract; unverified
            • HumanEnhancement of iron, zinc, and calcium bioaccessibility and bioavailability in green gram (Vigna radiata L.) supplemented with buttermilk through phytate reduction: an in vitro dietary evaluation.
              Front Nutr, 2026 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
              PMID 41693945DOI 10.3389/fnut.2026.1756171PMC12900709 (free full text)PDF
              Verification: full-text auto-extracted verbatim snippets with location; needs human check
              • Key findings · abstract:Moreover, the bioavailability of these micronutrients is evaluated by treating Caco-2 cells with the final digest and analyzing them using ICP-MS.
              • Key findings · abstract:Improved bio accessibility and bioavailability were underlined by a significant rise of 68% in iron, 57% in calcium, and 23% in zinc in the buttermilk treated samples.
              • Form comparison · full text, Section 'Bio accessibility and bioavailability of':Although zinc bio accessibility increased by 19%, a lesser extent compared to iron and calcium, this trend is consistent with earlier reports indicating that zinc bio accessibility is strongly influenced by the presence of chelating compounds and antinutritional factors; fermentation and probiotic activity in buttermilk may partially mitigate these inhibitory effects by degrading zinc-binding comp
            • HumanIdentification of novel calcium-absorption promoting peptides from lactopontin gastrointestinal digests and investigation of their intestinal calcium transport mechanism.
              Food Chem, 2026 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 42468233DOI 10.1016/j.foodchem.2026.150439
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:CaCl2 group, with lower intracellular calcium retention (accelerated Ca2+ efflux).
              • Key findings · abstract:MS confirmed KLS(+79.97)QEFH's intact intestinal absorption via stable calcium-chelating structure.
            • HumanComparison of calcium citrate and calcium carbonate absorption in patients with a Roux-en-Y gastric bypass, sleeve gastrectomy, and one-anastomosis gastric bypass: a double-blind, randomized cross-over trial.
              Surg Obes Relat Dis, 2025 · Design: randomized; crossover; double-blind · abstract only (PubMed) · open access (green)
              PMID 39603923DOI 10.1016/j.soard.2024.10.034
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:The intestinal absorption of Ca carbonate and Ca citrate among groups divided by surgical procedure was compared over 8 hours of testing.
              • Key findings · abstract:Measurements included serum and urine Ca concentrations for peak values (Cmax) and area under the curve (AUC0-8h), along with parathyroid hormone (PTH) levels to calculate minimum PTH (PTHmin) and cumulative PTH decline (AUC0-8h).
              • Key findings · abstract:Ca citrate also demonstrated superior relative bioavailability, as evidenced by a higher AUC0-8h of 76.1 mg/dL·h versus 74.7 mg/dL·h for carbonate (P = .001) and a Cmax of 9.8 mg/dL compared to 9.5 mg/dL for carbonate (P < .001[excerpt truncated in our database — see source]
              • Cmax · abstract:Measurements included serum and urine Ca concentrations for peak values (Cmax) and area under the curve (AUC0-8h), along with parathyroid hormone (PTH) levels to calculate minimum PTH (PTHmin) and cumulative PTH decline (AUC0-8h).
              • Cmax · abstract:Ca citrate also demonstrated superior relative bioavailability, as evidenced by a higher AUC0-8h of 76.1 mg/dL·h versus 74.7 mg/dL·h for carbonate (P = .001) and a Cmax of 9.8 mg/dL compared to 9.5 mg/dL for carbonate (P < .001).
              • AUC · abstract:Measurements included serum and urine Ca concentrations for peak values (Cmax) and area under the curve (AUC0-8h), along with parathyroid hormone (PTH) levels to calculate minimum PTH (PTHmin) and cumulative PTH decline (AUC0-8h).
              • AUC · abstract:Ca citrate also demonstrated superior relative bioavailability, as evidenced by a higher AUC0-8h of 76.1 mg/dL·h versus 74.7 mg/dL·h for carbonate (P = .001) and a Cmax of 9.8 mg/dL compared to 9.5 mg/dL for carbonate (P < .001).
              • Relative bioavailability · abstract:Ca citrate also demonstrated superior relative bioavailability, as evidenced by a higher AUC0-8h of 76.1 mg/dL·h versus 74.7 mg/dL·h for carbonate (P = .001) and a Cmax of 9.8 mg/dL compared to 9.5 mg/dL for carbonate (P < .001).
            • HumanAbsorption, Scintigraphy, Efficacy and Tolerability of Short-Term Calcium Carbonate Supplementation in Healthy Subjects.
              Cureus, 2025 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
              PMID 40786390DOI 10.7759/cureus.87642PMC12335733 (free full text)PDF
              Verification: full-text auto-extracted verbatim snippets with location; needs human check
              • Key findings · abstract:Post-dosing, a gradual rise in serum calcium concentration was observed and the peak increment in serum calcium (4.13±0.38 µg/mL) was reached at four hours.
              • Key findings · abstract:The bioavailability, determined as the area under the curve for six hours (ΔAUC0-6) of serum calcium, was 38.2±4.8 µg/mL/hour.
              • Key findings · abstract:An increase in mean serum calcium (~3%) and procollagen type 1 N-terminal propeptide (P1NP) (~13.2%) was observed post-treatment.
              • Key findings · abstract:Dual-energy X-ray absorptiometry (DEXA) scan results revealed an increase in bone density from 1.1968±0.05 (baseline) to 1.2115±0.06 g/cm2, post-treatment.
              • AUC · abstract:The bioavailability, determined as the area under the curve for six hours (ΔAUC0-6) of serum calcium, was 38.2±4.8 µg/mL/hour.
              • Form comparison · full text, Section 'Results':At the end of the study period (four weeks), a modest but important increase in mean serum calcium (~3%) and P1NP level (~13.2%) was observed compared to baseline.
            • HumanGlycated walnut peptide-calcium chelates: Structural properties, calcium absorption enhancement mechanism, and osteogenic effects.
              Food Chem, 2025 · Design: not stated · abstract only (PubMed) · open access (green)
              PMID 40482493DOI 10.1016/j.foodchem.2025.145039
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:This study examines the structural characteristics of a novel glycated walnut peptide‑calcium chelate (COS-AERGVLYR-Ca), explores its mechanisms of calcium absorption and transport, and investigates its impact on osteoblast MC3T3-E1 cells.
              • Key findings · abstract:Furthermore, COS-AERGVLYR effectively resisted the inhibition of anti-nutritional factors on Ca2+ absorption and facilitated calcium ion transport via TRPV6 and CAV1.3 channels, significantly promoting the proliferation and mineralization of osteoblast MC3T3-E1 cells.
            • HumanPreparation, structural characterisation, absorption and calcium transport studies of walnut peptide calcium chelate.
              Food Funct, 2025 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 39744816DOI 10.1039/d4fo04403g
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:Furthermore, using the Caco-2 cell monolayer model, WP-Ca was shown to significantly increase calcium bioavailability and effectively reverse the inhibitory effects of dietary factors (phytates and phosphates) on calcium absorption.
            • HumanInfluence of concurrent oral calcium carbonate supplementation on steady-state pharmacokinetics of once daily oral raltegravir in persons with HIV: a protocol for a prospective open-label non-randomised study in Canada.
              BMJ Open, 2025 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
              PMID 40617620DOI 10.1136/bmjopen-2024-094384PMC12228467 (free full text)
              Verification: full-text auto-extracted verbatim snippets with location; needs human check
              • Cmax · full text, Table 1:ts, blood count, serum creatinine) CD4 and plasma viral load Pregnancy test (urine) PK outcomes Baseline concentration (C0h) Maximum concentration (Cmax) Peak to reach maximum drug concentration (Tmax) Concentration 24 hours post-dose (C24) Minimum concentration (Cmin) Half-life (T1/2) 24 hours area under the concentration-time curve (AUC0-24)
              • Cmax · full text, Section 'Updated recommendation for raltegravir a':According to the product monograph of Isentress HD 1200 mg (2×600 mg) and to the HIV treatment guideline, recommendations are for no co-administration of raltegravir with calcium carbonate.25 Previous work reported a notable decrease in oral absorption, reflected by the reduction in steady-state Cmax AUC0-24, and C24 by 74, 72 and 48% when raltegravir was administered concomitantly with a 3000 mg
              • Tmax · full text, Table 1:a viral load Pregnancy test (urine) PK outcomes Baseline concentration (C0h) Maximum concentration (Cmax) Peak to reach maximum drug concentration (Tmax) Concentration 24 hours post-dose (C24) Minimum concentration (Cmin) Half-life (T1/2) 24 hours area under the concentration-time curve (AUC0-24)
              • AUC · full text, Table 1:(Cmax) Peak to reach maximum drug concentration (Tmax) Concentration 24 hours post-dose (C24) Minimum concentration (Cmin) Half-life (T1/2) 24 hours area under the concentration-time curve (AUC0-24)
              • AUC · full text, Section 'Updated recommendation for raltegravir a':According to the product monograph of Isentress HD 1200 mg (2×600 mg) and to the HIV treatment guideline, recommendations are for no co-administration of raltegravir with calcium carbonate.25 Previous work reported a notable decrease in oral absorption, reflected by the reduction in steady-state Cmax AUC0-24, and C24 by 74, 72 and 48% when raltegravir was administered concomitantly with a 3000 mg
              • Form comparison · full text, Section 'Outcome measures':The geometric mean of trough concentration (C24) for each of the three periods will be compared with two reference values: 13.8 ng/mL, which corresponds to the mean in vitro 95% inhibitory concentration of raltegravir for wild-type HIV-1,30 and 20 ng/mL which represents the ‘target’ Ctrough threshold associated with therapeutic response.31 32
            • HumanCalcium-loaded lipopeptides for enhanced bioavailability and reduction of calcium deficiency.
              Int J Biol Macromol, 2025 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 41241342DOI 10.1016/j.ijbiomac.2025.149025
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:Two types of ELC-based complexes were prepared using CaCO3 and CaCl2, and characterization techniques confirmed the incorporation of calcium salts into the ELC matrix.
            • HumanIdentification of a novel calcium-binding peptide from Lentinula edodes and structure, stability and absorption evaluation of its calcium chelate.
              J Sci Food Agric, 2025 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 40254539DOI 10.1002/jsfa.14292
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:RESULTS: The LE protein hydrolysate was sequentially purified using ultrafiltration followed by anion-exchange chromatography; two subfractions (F33 and F34) of LE CBP were obtained, both of which exhibited higher calcium binding rate.
              • Key findings · abstract:CONCLUSION: LE can be used to prepare peptide-chelate with high calcium absorption. © 2025 Society of Chemical Industry.
            • HumanPhysicochemical properties, in vitro digestion and absorption of bio‑calcium powders derived from Asian seabass gills as affected by bleaching treatment.
              Food Chem, 2025 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 41240855DOI 10.1016/j.foodchem.2025.147080
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:Using Caco-2 cell monolayer, a significantly higher Ca absorption was observed in both BCPs (49.5-42.2 %), compared to CaCO3 (35 %) (p < 0.05), particularly in BCP-NBG.
            • HumanGlycated walnut meal peptide‑calcium chelates (COS-MMGGED-Ca): Preparation, characterization, and calcium absorption-promoting.
              Food Chem, 2025 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 39197240DOI 10.1016/j.foodchem.2024.140975
              Verification: abstract-only auto-extract; unverified
              • Key findings · abstract:Furthermore, COS-MMGGED significantly enhanced Ca2+ transport across Caco-2 monolayers, 1.13-fold and 1.62-fold higher than CaCl2 and MMGGED, respectively, at 240 h.
              • Relative bioavailability · abstract:Furthermore, COS-MMGGED significantly enhanced Ca2+ transport across Caco-2 monolayers, 1.13-fold and 1.62-fold higher than CaCl2 and MMGGED, respectively, at 240 h.
            • HumanInvestigation of the occurrence and sources of calcium (Ca) in urinary stones using synchrotron radiation based X-ray fluorescence and X-ray absorption spectroscopy (XAS).
              Anal Methods, 2025 · Design: not stated · abstract only (PubMed) · closed/paywalled
              PMID 41347338DOI 10.1039/d5ay01402f
              Verification: abstract-only auto-extract; unverified
              • HumanCalcium absorption dynamics in the presence of ferrous salts.
                Food Res Int, 2025 · Design: not stated · abstract only (PubMed) · open access (hybrid)
                PMID 40597553DOI 10.1016/j.foodres.2025.116853
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Using a Caco-2 cell model, we examined the absorption of calcium chloride, calcium lactate, and calcium gluconate, and the effects of corresponding ferrous salts on their absorption.
                • Key findings · abstract:Calcium lactate demonstrated the highest absorption rate (6.03 % ± 0.7 %), followed by calcium gluconate (5.40 % ± 0.58 %) and calcium chloride (4.97 % ± 0.23 %).
                • Key findings · abstract:Analysis of calcium transport pathways revealed that ferrous salts did not significantly affect TRPV6 and claudin-2 expression but decreased calbindin-D9k expression, potentially reducing intracellular calcium retention.
                • Key findings · abstract:The study also found that f[excerpt truncated in our database — see source]
              • HumanSuperior bioavailability of the calcium salt form of β-hydroxy-β-methylbutyrate compared with the free acid form.
                Amino Acids, 2024 · Design: crossover · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 38564019DOI 10.1007/s00726-023-03369-zPMC10987370 (free full text)
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Key findings · abstract:The following parameters were calculated: peak plasma (Cmax), time to peak (Tmax), slope of HMB appearance in blood, area under the curve (AUC), half-life time (t1/2) and relative bioavailability (HMB-Ca in water set as reference).
                • Key findings · abstract:HMB-Ca in capsules and in water showed similar plasma HMB values across time (p = 0.438).
                • Key findings · abstract:AUC (HMB-Ca in capsules: 50,078 ± 10,507;[excerpt truncated in our database — see source]
                • Key findings · abstract:HMB-FA: 29,130 ± 12,946 µmol L-1 × 720 min), Cmax (HMB-Ca in capsules: 229.2 ± 65.9;[excerpt truncated in our database — see source]
                • Key findings · abstract:HMB-FA: 139.1 ± 67.2 µmol L-1) and relative bioavailability (HMB-Ca in capsules: 104.8 ± 14.9%;[excerpt truncated in our database — see source]
                • Cmax · abstract:The following parameters were calculated: peak plasma (Cmax), time to peak (Tmax), slope of HMB appearance in blood, area under the curve (AUC), half-life time (t1/2) and relative bioavailability (HMB-Ca in water set as reference).
                • Cmax · abstract:HMB-FA: 29,130 ± 12,946 µmol L-1 × 720 min), Cmax (HMB-Ca in capsules: 229.2 ± 65.9;
                • Tmax · abstract:The following parameters were calculated: peak plasma (Cmax), time to peak (Tmax), slope of HMB appearance in blood, area under the curve (AUC), half-life time (t1/2) and relative bioavailability (HMB-Ca in water set as reference).
                • Tmax · abstract:HMB-Ca in water resulted in the fastest Tmax (43 ± 22 min) compared to HMB-Ca in capsules (79 ± 40 min) and HMB-FA (78 ± 21 min) (all p < 0.05), while t1/2 was similar between treatments.
                • AUC · abstract:The following parameters were calculated: peak plasma (Cmax), time to peak (Tmax), slope of HMB appearance in blood, area under the curve (AUC), half-life time (t1/2) and relative bioavailability (HMB-Ca in water set as reference).
                • AUC · abstract:AUC (HMB-Ca in capsules: 50,078 ± 10,507;
                • Relative bioavailability · abstract:The following parameters were calculated: peak plasma (Cmax), time to peak (Tmax), slope of HMB appearance in blood, area under the curve (AUC), half-life time (t1/2) and relative bioavailability (HMB-Ca in water set as reference).
                • Relative bioavailability · abstract:HMB-FA: 139.1 ± 67.2 µmol L-1) and relative bioavailability (HMB-Ca in capsules: 104.8 ± 14.9%;
                • Relative bioavailability · full text, Section 'Calculation of pharmacokinetic parameter':For the relative bioavailability calculation, HMB-Ca was set as the reference treatment as thus arbitrarily set as 100%;
                • Relative bioavailability · full text, Section 'Plasma HMB responses to HMB-Ca and HMB-F':Panel c: Relative bioavailability of the different forms of HMB using HMB-Ca dissolved in water as reference and thereby arbitrarily set as 100%.
                • Form comparison · full text, Section 'Plasma HMB responses to HMB-Ca and HMB-F':HMB-FA at the initial 60 min after ingestion (all p < 0.05) whereas HMB-Ca in capsules resulted in higher plasma HMB concentrations vs.
              • HumanComparative Evaluation of Bioavailability, Efficacy and Safety of MICROCORE NESC® with Calcium Carbonate and Calcium Citrate Malate in Osteopenic and Osteoporotic Patients: A Randomized Clinical Trial.
                Indian J Orthop, 2024 · Design: randomized · abstract only (PubMed) · open access (green)
                PMID 38694695DOI 10.1007/s43465-024-01117-3PMC11058142 (free full text)
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Higher percentage of improvement in calcium absorption as depicted by an increase in serum calcium levels (10.23%) in the MICROCORE NESC®-treated group when compared to Shelcal (7.7%) and CCM (7.2%).
                • Key findings · abstract:The relative bioavailability of MICROCORE NESC® with respect to Shelcal was 93%.
                • Relative bioavailability · abstract:The relative bioavailability of MICROCORE NESC® with respect to Shelcal was 93%.
              • HumanIdentifying Gut Microbiome Features that Predict Responsiveness Toward a Prebiotic Capable of Increasing Calcium Absorption: A Pilot Study.
                Calcif Tissue Int, 2024 · Design: crossover; stable-isotope · full text (Europe PMC XML) + abstract · open access (hybrid)
                PMID 38656326DOI 10.1007/s00223-024-01201-8PMC11061023 (free full text)
                Verification: full text read; no PK numbers matched
                • Key findings · abstract:In this secondary analysis, we compared differences in relative microbiota taxa abundance between responders (greater than or equal to 3% increase in Ca absorption) and non-responders (less than 3% increase).
                • Key findings · abstract:Dual stable isotope methodologies were used to assess fractional Ca absorption at the end of crossover treatments with placebo, 10, and 20 g/day of soluble corn fiber (SCF).
              • HumanPopulation pharmacokinetics of oral fosfomycin calcium in healthy women.
                J Antimicrob Chemother, 2024 · Design: randomized · full text (Europe PMC XML) + abstract · open access (hybrid)
                PMID 39205651DOI 10.1093/jac/dkae295PMC11531824 (free full text)
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Key findings · abstract:METHODS: A clinical trial (a randomized, open-label, bioavailability study of single and multiple doses of 1000 mg capsules, single dose of 500 mg capsule and single dose of 250 mg/5 mL suspension of oral fosfomycin calcium under fasted conditions in healthy women volunteers, Code: PD7522.22, EudraCT: 2020-001664-28) was carried out at the Clinical Trial Unit, Araba University Hospital (Vitoria-Gasteiz, Spain).
                • Key findings · abstract:Twenty-four healthy women were included in the study, and plasma samples were collected at different times over a period of 24 h.
                • Key findings · abstract:The concentration-time data of fosfomycin in plasma[excerpt truncated in our database — see source]
                • Food effect · abstract:METHODS: A clinical trial (a randomized, open-label, bioavailability study of single and multiple doses of 1000 mg capsules, single dose of 500 mg capsule and single dose of 250 mg/5 mL suspension of oral fosfomycin calcium under fasted conditions in healthy women volunteers, Code: PD7522.22, EudraCT: 2020-001664-28) was carried out at the Clinical Trial Unit, Araba University Hospital (Vitoria-Gasteiz, Spain).
                • Cmax · full text, Section 'Demographics, clinical characteristics a':Thus, Cmax ranged from 1.1 to 5.2 mg/L with 500 mg capsules, from 1.2 to 7.0 mg/L with 1000 mg capsules, from 2.5 to 9.5 mg/L with 1000 mg suspension and from 4.3 to 12.3 mg/L with the multiple-dose regimen (1000 mg q8h, 3 days).
                • Cmax · full text, Section 'Demographics, clinical characteristics a':Regardless of the group, the time to reach Cmax (tmax) ranged from 1 to 4.5 h.
                • Tmax · full text, Section 'Demographics, clinical characteristics a':Regardless of the group, the time to reach Cmax (tmax) ranged from 1 to 4.5 h.
                • Form comparison · full text, Section 'Population PK modelling':Non-parametric medians and 95% (2.5th and 97.5th percentiles) confidence intervals (CIs) of pharmacokinetic parameters were obtained and compared with final model estimates.
              • HumanAn Algorithm to Assess Calcium Bioavailability from Foods.
                J Nutr, 2024 · Design: not stated · abstract only (PubMed) · open access (hybrid)
                PMID 38072154DOI 10.1016/j.tjnut.2023.12.005
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:RESULTS: Data from 496 observations were modeled to develop a predictive algorithm for calcium bioavailability in adults on the basis of calcium load and oxalate and phytate loads, which represent the 2 main inhibitors of calcium absorption.
              • HumanLoad carriage exercise increases calcium absorption and retention in healthy young women.
                J Bone Miner Res, 2024 · Design: randomized; crossover; stable-isotope · abstract only (PubMed) · open access (hybrid)
                PMID 38630876DOI 10.1093/jbmr/zjad003
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:On day 1, urinary Ca was lower in the EX pool (25 ± 11 mg) compared to REST (38 ± 16 mg, P = .001), but did not differ over the full 24-h collection (P > .05).
                • Key findings · abstract:FCA was greater during EX (26.6 ± 8.1%) compared to REST (23.9 ± 8.3%, P < .05).
              • HumanCaseinophosphopeptides Overcome Calcium Phytate Inhibition on Zinc Bioavailability by Retaining Zinc from Coprecipitation as Zinc/Calcium Phytate Nanocomplexes.
                J Agric Food Chem, 2024 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 38380599DOI 10.1021/acs.jafc.3c07495
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Caseinophosphopeptides-stabilized Zn/CaPA-NCs were found to deliver bioavailable nanoparticulate zinc in mouse jejunal loop ex vivo model and polarized Caco-2 cells, and the treatments with specific inhibitors revealed that intestinal zinc absorption from Zn/CaPA-NCs invoked macropinocytosis, lysosomal release into the cytosol, and transcytosis.
              • HumanIdentification of calcium chelating peptides from peanut protein hydrolysate and absorption activity of peptide-calcium complex.
                J Sci Food Agric, 2024 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 38545944DOI 10.1002/jsfa.13493
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:RESULTS: Peptides with high calcium chelating rate were isolated and purified from peanut protein hydrolysate (PPH), and the chelation rate of component F21 was higher (81.4 ± 0.8%).
                • Key findings · abstract:Six peptides were identified from component F21 by liquid chromatography-tandem mass spectrometry, and the frequency of acidic amino acids and arginine in the amino acid sequence was higher in all six peptides.
                • Key findings · abstract:Caco-2 cell model tests revealed that the bioavailability of PPH21-Ca was 58.4 ± 0.5%, which was significantly higher than that of inorganic calcium at 37.0 ± 0.4%.
                • Key findings · abstract:This study provides a theoretical b[excerpt truncated in our database — see source]
                • Fractional absorption · abstract:This study provides a theoretical basis for the development of new calcium supplement products that are absorbed easily. © 2024 Society of Chemical Industry.
              • HumanComparative Effectiveness of Ascorbic Acid vs. Calcium Ascorbate Ingestion on Pharmacokinetic Profiles and Immune Biomarkers in Healthy Adults: A Preliminary Study.
                Nutrients, 2024 · Design: randomized; crossover; double-blind · n: n = 27 · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 39408325DOI 10.3390/nu16193358PMC11479081 (free full text)
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Key findings · abstract:Conversely, there was evidence that ingestion of 500 mg of CA increased DHA in plasma, increased neutrophil functionality during the first 8 h of the PK study, promoted increased natural killer cells, and altered weight-adjusted PK profiles, suggesting greater volume distribution and clearance from the blood.
                • Cmax · full text, Section '5.1. Primary Outcomes':The same research group completed a follow-up study with 40 healthy adults who supplemented 1000 mg CA compared to AA and found higher Cmax plasma and leukocyte vitamin C concentrations, though the mean percent change from baseline in plasma vitamin C was similar compared to AA control [1].
                • Cmax · full text, Section '5.1. Primary Outcomes':Interestingly, Purpura and colleagues [8] reported that ingesting 500 mg of a liposomal coated source of L-ascorbic acid promoted a significantly higher Cmax (plasma +27%, leukocytes +20%, and 24 h AUC (plasma +21%, leukocytes +8%) compared to AA.
                • AUC · full text, Section '4.3. Plasma Vitamin C Concentrations':However, CA yielded significantly higher DHA AUC values compared to AA, while AA yielded higher ASC compared to CA, when consuming 500 mg doses.
                • AUC · full text, Section '5.1. Primary Outcomes':Findings indicate no differences between the different forms of vitamin C in AUC values of ASC, DHA, or total vitamin C with 250 mg supplementation.
                • AUC · full text, Section '5.1. Primary Outcomes':However, acute supplementation with 500 mg CA significantly enhanced ASC conversion to DHA, indicated by higher AUC values, in the plasma and greater retention of ASC in lymphocytes.
                • Food effect · full text, Section '2.3. Experimental Timeline':Participants then returned to the lab in a fasted state the next morning (about 8:00 am) for a 24 h blood sample.
                • Form comparison · full text, Section '4.3. Plasma Vitamin C Concentrations':However, CA yielded significantly higher DHA AUC values compared to AA, while AA yielded higher ASC compared to CA, when consuming 500 mg doses.
                • Form comparison · full text, Section '5.1. Primary Outcomes':We examined the effects of 250 mg and 500 mg CA vs.
                • Form comparison · full text, Section '5.1. Primary Outcomes':In this regard, results indicate acute supplementation with lower doses of CA is not sufficient to elicit enhanced absorption and retention of ASC and/or DHA in plasma and/or lymphocytes compared to commercially available AA; however, a higher dose (500 mg) of CA did significantly enhance vitamin C absorption kinetics.
              • HumanCharacterization and Mechanism of a Novel Rice Protein Peptide (AHVGMSGEEPE) Calcium Chelate in Enhancing Calcium Absorption in Caco-2 Cells.
                J Agric Food Chem, 2024 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 38563891DOI 10.1021/acs.jafc.3c09916
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Furthermore, this study demonstrated that the 4 mmol/L AHV-Ca chelate (61.75 ± 13.23 μg/well) significantly increases calcium absorption compared to 1 mM CaCl2 (28.57 ± 8.59 μg/well) in the Caco-2 cell monolayer.
              • HumanCharacterization of percutaneous absorption of calcium, magnesium, and potentially toxic elements in two tailored sulfurous therapeutic peloids: a comprehensive in vitro pilot study.
                Int J Biometeorol, 2024 · Design: not stated · full text (Europe PMC XML) + abstract · open access (hybrid)
                PMID 38427095DOI 10.1007/s00484-024-02644-2PMC11108904 (free full text)
                Verification: full text read; no PK numbers matched
                • Key findings · abstract:To replicate the pelotherapy methodology, an in vitro permeation experiment was conducted using a vertical diffusion chamber (Franz cells) and a biological system with human skin membranes from five Caucasian women, age range between 25 and 51 years.
              • HumanCalcium absorption by Alaska pollock surimi protein hydrolysate promotes osteoblast differentiation.
                J Food Sci, 2024 · Design: not stated · abstract only (PubMed) · open access (hybrid)
                PMID 38369943DOI 10.1111/1750-3841.16988
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Evaluation of the calcium absorption-promoting ability of APSH revealed that the best calcium-binding ability was achieved after hydrolysis with a combination of pepsin, α-chymotrypsin, and trypsin, and separation into <3 kDa (APSH-I), 3-5 kDa (APSH-II), 5-10 kDa (APSH-III), and <10 kDa (APSH-IV) fractions.
                • Key findings · abstract:Comparison of the calcium absorption capacity using Caco-2 cells showed that calcium absorption was promoted by these hydrolysates.
              • HumanEarly decrease of ionized calcium and static symmetric dimethylarginine concentration in a model of renal tubular necrosis in corn snakes (Pantherophis guttatus).
                Am J Vet Res, 2024 · Design: not stated · abstract only (PubMed) · open access (gold)
                PMID 38029521DOI 10.2460/ajvr.23.09.0204
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Plasma biochemistry and blood gas analyses were performed at baseline and after the 3rd and 11th injections.
              • HumanFunctional hypoxia reduces mitochondrial calcium uptake.
                Redox Biol, 2024 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 38401291DOI 10.1016/j.redox.2024.103037PMC10906399 (free full text)PDF
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Form comparison · full text, Section 'Myotubes reduce mitochondrial Ca2+ uptak':E) Hypoxia and glycolysis hallmark gene sets enriched in myotubes 120 min after exposure to 1 % O2 compared with 5 % O2 in the gas phase (N = 6).
                • Form comparison · full text, Section 'Myotubes reduce mitochondrial Ca2+ uptak':HIF1α protein (Fig. 3C-D) and the “Hypoxia” and “Glycolysis” hallmark gene-sets (Fig. 3E, Dataset S1) were among those enriched in myotubes exposed to 1 % compared with 5 % O2.
                • Form comparison · full text, Section 'Myotubes reduce mitochondrial Ca2+ uptak':However, mitochondrial Ca2+ uptake was lower in response to caffeine stimulation under 1 % compared with 5 % O2 (Fig. 3J and K) and occurred in the absence of changes of MCU protein content (Figs.
              • HumanBioavailability of calcium in an enriched postbiotic system compared to calcium citrate in healthy postmenopausal females; A randomized, double-blind, comparator-controlled, crossover study.
                Front Nutr, 2023 · Design: randomized; crossover; double-blind · n: 24 participants · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 37006928DOI 10.3389/fnut.2023.1073622PMC10050718 (free full text)
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Key findings · abstract:After a 14-h (overnight) fast followed by a single dose of product with a standard low-calcium breakfast, both serum and urine calcium concentrations were assessed for up to 8 and 24 h, respectively.
                • Food effect · abstract:After a 14-h (overnight) fast followed by a single dose of product with a standard low-calcium breakfast, both serum and urine calcium concentrations were assessed for up to 8 and 24 h, respectively.
                • Cmax · full text, Table 2:09) 2.35 (0.08) 2.37 (0.08) iAUC0-8h(mmol/L*h) 0.86 (0.51)a 0.52 (0.45)b 0.60 (0.49)b AUCT0-8h (mmol/L*h) 19.72 (0.74)a 19.34 (0.68)b 19.14 (2.13)a,b Cmax (mmol/L) 2.57 (0.11)a 2.50 (0.10)b 2.54 (0.10)a tmax (h)† 4.0 (2.0–7.0) 4.0 (1.5–8.0) 5.5 (2.0–8.0) Urine Pre-dose urine calcium normalized to creatinine (mmol/mmol) 0.29 (0.19) 0.29 (0.18) 0.30 (0.21) Pre-dose excreted calcium (mg) 5.83 (3.8
                • Cmax · full text, Section 'Urine calcium':AUCT0-10h, AUCT0-24h, and Cmax were significantly higher for Ca-LAB compared to calcium citrate (p < 0.001, p = 0.006, and p < 0.001, respectively) and Ca-SC (p < 0.001, p = 0.003, and p < 0.001, respectively).
                • Tmax · full text, Table 2:0.51)a 0.52 (0.45)b 0.60 (0.49)b AUCT0-8h (mmol/L*h) 19.72 (0.74)a 19.34 (0.68)b 19.14 (2.13)a,b Cmax (mmol/L) 2.57 (0.11)a 2.50 (0.10)b 2.54 (0.10)a tmax (h)† 4.0 (2.0–7.0) 4.0 (1.5–8.0) 5.5 (2.0–8.0) Urine Pre-dose urine calcium normalized to creatinine (mmol/mmol) 0.29 (0.19) 0.29 (0.18) 0.30 (0.21) Pre-dose excreted calcium (mg) 5.83 (3.81) 7.27 (13.67) 5.40 (5.30) AUCT0-10h (mmol/mmol*h) 9
                • AUC · full text, Table 2:rate Mean (SD) Serum Pre-dose serum calcium (mmol/L) 2.36 (0.09) 2.35 (0.08) 2.37 (0.08) iAUC0-8h(mmol/L*h) 0.86 (0.51)a 0.52 (0.45)b 0.60 (0.49)b AUCT0-8h (mmol/L*h) 19.72 (0.74)a 19.34 (0.68)b 19.14 (2.13)a,b Cmax (mmol/L) 2.57 (0.11)a 2.50 (0.10)b 2.54 (0.10)a tmax (h)† 4.0 (2.0–7.0) 4.0 (1.5–8.0) 5.5 (2.0–8.0) Urine Pre-dose urine calcium normalized to creatinine (mmol/mmol) 0.29 (0.19)
                • AUC · full text, Section 'Bioavailability parameters':Incremental area under the curve (iAUC) from 0 to 8 h was calculated for serum calcium by determining the area under the curve above the baseline value using the trapezoid method.
                • AUC · full text, Section 'Bioavailability parameters':Total area under the curve (AUCT) from 0 to 8 h for serum calcium, and 0 to 10 and 24 h for urine calcium were derived from individual concentration-time plots for each participant using the trapezoid method.
                • Food effect · full text, Section 'Study protocol':Prior to the intervention days, i.e., day’s −1, 8, and 16, participants fasted for 14 h and were only instructed to drink 600 mL distilled water 12 h prior to administration and 300 mL distilled water 9 h prior to administration.
                • Food effect · full text, Section 'Study protocol':Under fasting conditions, a pre-intervention blood sample was collected, and participants emptied their bladder again and the overall urinary output was collected over a time window of 2 h prior administration.
                • Form comparison · full text, Section 'Serum calcium':Increment in serum calcium concentration was significantly higher following Ca-LAB administration compared to calcium citrate and Ca-SC, from 2 to 5 h post dose and from 2 to 6 h post dose, respectively.
                • Form comparison · full text, Section 'Serum calcium':Following calcium citrate administration, there was no significant difference in serum calcium concentration compared to Ca-SC post dose up to 5 h but increment serum calcium was significantly higher at 6 h post dose.
                • Form comparison · full text, Section 'Serum calcium':Ca-LAB had higher iAUC0-8h compared to calcium citrate (p = 0.006) and Ca-SC (p = 0.004).
              • HumanA Novel Low Molecule Peptides-calcium Chelate from Silkworm Pupae Protein Hydrolysate: Preparation, Antioxidant Activity, and Bioavailability.
                Curr Pharm Des, 2023 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 37021416DOI 10.2174/1381612829666230404134044
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:METHODS: Optimize the preparation parameters of silkworm pupae bioactive peptide-calcium chelate, and investigate the mechanism and bioavailability of silkworm pupae active peptide as a transport carrier to promote calcium ion absorption using simulated gastrointestinal digestion and Caco-2 monolayer cell model.
                • Key findings · abstract:The DPPH radical scavenging activity of silkworm pupae protein hydrolysatecalcium chelate was 79.36 ± 4.31%, significantly higher than silkworm pupae protein hydrolysate (61.00 ± 9.56%).
                • Key findings · abstract:The particle size of the silkworm pupae protein hydrolysate-calcium chelate was 970.75 ± 30.12[excerpt truncated in our database — see source]
              • HumanPharmacokinetic/Pharmacodynamic Analysis of Oral Calcium Fosfomycin: Are Urine Levels Sufficient to Ensure Efficacy for Urinary Tract Infections?
                Pharmaceutics, 2023 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 37111669DOI 10.3390/pharmaceutics15041185PMC10144240 (free full text)
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Key findings · abstract:The accumulated fraction of fosfomycin excreted in urine was around 18%, consistent with its low oral bioavailability and its almost exclusively renal clearance by glomerular filtration as unchanged drug.
                • Cmax · full text, Table 3:Cmax and Cmax/MIC ratio of urine fosfomycin in the volunteers receiving fosfomycin at different dose levels. Values expressed as mean ± standard deviation. In parenthesis, maximum and minimum values. Cmax(mg/L) Cmax/4 Cmax/8 500 mg single dose 133.72 ±
                • Cmax · full text, Section '3. Results':Table 3 shows the maximum concentration (Cmax) of fosfomycin in the urine samples, as well as the Cmax to MIC ratios for MICs of 4 and 8 mg/L, the tentative epidemiological cut-off (TECOFF) and the clinical breakpoint for E. coli reported by EUCAST, respectively.
                • Cmax · full text, Section '3. Results':After administration of the 500 mg single dose, the Cmax was 33 and 16 times higher than the TECOFF and the clinical breakpoint for E. coli, respectively.
                • AUC · full text, Table 4:AUCurine,24/MIC distribution (mean, median, and 2.5% percentile) and CFR values. CFR (%) 2.5% Percentile Median Mean 500 mg single dose 97 16 1166 1816 1000 mg single dose 98 24 1743 2711 1000 mg q8h, 3 days 98 54 3516 5515
                • AUC · full text, Section '2.4. Pharmacokinetic/Pharmacodynamic (PK':Additionally, the area under the urine concentration curve in a period of 24 h (AUCurine,24) was calculated with the trapezoidal rule by assuming that the drug concentration remains constant in the urinary bladder during each time interval [16].
                • AUC · full text, Section '2.4. Pharmacokinetic/Pharmacodynamic (PK':For every MIC value and considering the variability of the AUCurine,24, the output of the simulation consisted of a probability distribution, and the mean, median, and 95% confidence interval (CI) (expressed as percentiles) of the AUCurine,24/MIC were extracted.
                • Relative bioavailability · full text, Section '3. Results':After administration of the 500 mg single dose, the Cmax was 33 and 16 times higher than the TECOFF and the clinical breakpoint for E. coli, respectively.
                • Food effect · full text, Section '2.2. Fosfomycin Administration':When subjects received the single dose of calcium fosfomycin, they were fasted for at least 8 h prior to dosing to 4 h post dose.
                • Food effect · full text, Section '2.2. Fosfomycin Administration':In the case of multiple doses, women were fasted for at least 8 h prior to the last dosing (day 4).
              • HumanIntestinal Calcium Absorption Decreases After Laparoscopic Sleeve Gastrectomy Despite Optimization of Vitamin D Status.
                J Clin Endocrinol Metab, 2023 · Design: stable-isotope · n: 35 women · abstract only (PubMed) · open access (green)
                PMID 36196648DOI 10.1210/clinem/dgac579PMC10091486 (free full text)
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Concurrently, median 1,25-dihydroxyvitamin D level increased from 60 (50-82) pg/mL to 86 (72-107) pg/mL (P < 0.01), without significant changes in parathyroid hormone or 24-hour urinary calcium levels.
                • Key findings · abstract:Those with lower postoperative FCA had greater areal BMD loss at the total hip (ρ = 0.45, P < 0.01).
              • HumanA novel calcium-binding peptide from bovine bone collagen hydrolysate and chelation mechanism and calcium absorption activity of peptide-calcium chelate.
                Food Chem, 2023 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 36621334DOI 10.1016/j.foodchem.2023.135387
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:The results of the calcium dialysis percentage and Caco-2 cells experiments showed that Glu-Tyr-Gly-Ca possessed good calcium transport activity and bioavailability.
              • HumanNovel Ca-Chelating Peptides from Protein Hydrolysate of Antarctic Krill (Euphausia superba): Preparation, Characterization, and Calcium Absorption Efficiency in Caco-2 Cell Monolayer Model.
                Mar Drugs, 2023 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 37999403DOI 10.3390/md21110579PMC10672039 (free full text)
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Key findings · abstract:Moreover, the VERG-Ca chelate is stable in gastrointestinal digestion and can significantly improve Ca transport in Caco-2 cell monolayer experiments, but phytate could significantly reduce the absorption of Ca derived from the VERG-Ca chelate.
                • Form comparison · full text, Section '2.7. Transport of VERG-Ca Chelate across':Compared with the CaCl2 group, VERG-Ca chelate-treated groups did not display remarkable Ca transport capability in Caco-2 cell monolayers from 30 to 60 min (p < 0.05).
              • HumanThe Postprandial Calcium Absorption of a Milk-Derived Calcium Permeate - The Acute RENEW Double-Blinded Randomized Controlled Cross-Over Study.
                J Nutr, 2023 · Design: randomized; crossover; double-blind · abstract only (PubMed) · open access (hybrid)
                PMID 37844839DOI 10.1016/j.tjnut.2023.10.005
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:RESULTS: Serum-ionized calcium concentration after the CC supplement was higher at 240 min compared with the CP supplement [between-group difference; 95% confidence interval (CI): 0.039 mmol/L; 95% CI: 0.017-0.061;[excerpt truncated in our database — see source]
                • Key findings · abstract:Serum-ionized calcium concentration after the CC supplement was significantly higher than placebo at all postprandial time points except at 60 min.
                • Key findings · abstract:Urinary calcium concentration in 360 min spot urine was higher after intake of CC compared with CP [between-group difference; 95% CI: 2.47 mmol/L; 95% CI: 1.90-3.03;[excerpt truncated in our database — see source]
                • Food effect · abstract:A fasting blood sample was collected at baseline, 60, 120, 240, and 360 min after ingestion.
                • Food effect · abstract:Serum-ionized calcium concentration after the CC supplement was significantly higher than placebo at all postprandial time points except at 60 min.
              • HumanModulation of fibroblast growth factor-23 expression and transepithelial calcium absorption in Caco-2 monolayer by calcium-sensing receptor and calcineurin under calcium hyperabsorptive state.
                Biochem Biophys Res Commun, 2023 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 37060830DOI 10.1016/j.bbrc.2023.04.013
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Fibroblast growth factor (FGF)-23 and calcium-sensing receptor (CaSR) have previously been postulated to be parts of a negative feedback regulation of the intestinal calcium absorption to prevent excessive calcium uptake and its toxicity.
                • Key findings · abstract:Herein, we induced calcium hyperabsorptive state (CHS) by exposing intestinal epithelium-like Caco-2 monolayer to 30 mM CaCl2 and 1,25-dihydroxyvitamin D3 [1,25(OH)2D3] after which FGF-23 mRNA levels and transepithelial calcium flux were determined.
                • Key findings · abstract:Although 10 nM 1,25(OH)2D3 was capable of enhancing transepithelial calcium flux, the higher-than-normal ca[excerpt truncated in our database — see source]
              • HumanDaily Intake of a Functional Synbiotic Yogurt Increases Calcium Absorption in Young Adult Women.
                J Nutr, 2022 · Design: randomized; crossover · n: n = 30 · abstract only (PubMed) · open access (bronze)
                PMID 35411924DOI 10.1093/jn/nxac088
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:OBJECTIVES: We investigated the acute effect in young adult women on calcium absorption of consuming (185 mL) a synbiotic yogurt (SYN) containing inulin (4 g) and Lactobacillus rhamnosus GG (>1 × 107 CFU/mL) compared with a control yogurt (CON).
                • Key findings · abstract:Habitual dietary intake, bone mineral density (BMD), calcium biomarkers, and serum 25-hydroxyvitamin D were measured at baseline.
                • Key findings · abstract:Calcium absorption was tested after each phase of the study using a 42Ca oral tracer.
                • Key findings · abstract:RESULTS: Net 42Ca recovered increased over time in each of the SYN and CON urine pools postdosing (Friedman, P < 0.001), with a tren[excerpt truncated in our database — see source]
              • HumanCalcium is a noncompetitive inhibitor of DMT1 on the intestinal iron absorption process: empirical evidence and mathematical modeling analysis.
                Am J Physiol Cell Physiol, 2022 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 36342159DOI 10.1152/ajpcell.00411.2022
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Iron absorption is a complex and highly controlled process where DMT1 transports nonheme iron through the brush-border membrane of enterocytes to the cytoplasm but does not transport alkaline-earth metals such as calcium.
                • Key findings · abstract:In this work, we investigate the effect of intracellular and extracellular calcium on iron uptake by Caco-2 cells, as determined by calcein fluorescence quenching.
                • Key findings · abstract:We found that extracellular calcium inhibits iron uptake by Caco-2 cells in a concentration-dependent manner.
              • HumanEnzymatically synthesized γ-[Glu](n≥1)-Gln as novel calcium-binding peptides to deliver calcium with enhanced bioavailability.
                Food Chem, 2022 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 35417842DOI 10.1016/j.foodchem.2022.132918
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:The particle size of chelates was 743.6 ± 64.2 nm and the chelates appeared stable neutral molecular entities with 91.33% of chelation rate and 35.2 mg/g of calcium, also with higher thermostability.
                • Key findings · abstract:The chelates could be used for food/nutraceutical applications, as no toxicity at 0.125-10 mg/mL and enhanced efficiency in calcium release (releasing percentage over 85% at pH 8.0), transport and uptake compared with CaCl2 were detected in Caco-2 cells.
              • HumanPrebiotic to Improve Calcium Absorption in Postmenopausal Women After Gastric Bypass: A Randomized Controlled Trial.
                J Clin Endocrinol Metab, 2022 · Design: randomized; double-blind; stable-isotope · abstract only (PubMed) · open access (hybrid)
                PMID 34888663DOI 10.1210/clinem/dgab883PMC8947782 (free full text)
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Other measures included tolerability, adherence, serum calciotropic hormones and bone turnover markers, and fecal microbial composition via 16S rRNA gene sequencing.
                • Key findings · abstract:Those with greater change in microbial composition following SCF treatment had greater increase in FCA (r2 = 0.72, P = 0.05).
              • HumanBiofilm accumulation and sucrose rinse modulate calcium and fluoride bioavailability in the saliva of children with early childhood caries.
                Sci Rep, 2022 · Design: not stated · n: n = 28 · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 35717506DOI 10.1038/s41598-022-14583-2PMC9206641 (free full text)
                Verification: full text read; no PK numbers matched
                • Key findings · abstract:This study aimed at investigating the combined effect of biofilm accumulation and 20% sucrose rinse on the modulation of calcium (Ca2+), phosphate (Pi), and fluoride (F-) bioavailability in the saliva of children with early childhood caries (ECC).
                • Key findings · abstract:The fluoride bioavailability was reduced by sucrose rinse and biofilm accumulation in CF and ECC children (p ≤ 0.002).
              • HumanApplication of a Mytilus edulis-derived promoting calcium absorption peptide in calcium phosphate cements for bone.
                Biomaterials, 2022 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 35124515DOI 10.1016/j.biomaterials.2022.121390
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:The PIE-calcium complex facilitated calcium uptake through the Caco-2 cell monolayers.
              • HumanPeptide-Calcium Chelate from Antler (Cervus elaphus) Bone Enhances Calcium Absorption in Intestinal Caco-2 Cells and D-gal-Induced Aging Mouse Model.
                Nutrients, 2022 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 36145113DOI 10.3390/nu14183738PMC9504974 (free full text)
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Key findings · abstract:Furthermore, the D-gal-induced aging mouse model indicated that the ABPs + AB-Ca group showed higher Ca and PINP levels, lower P, ALP, and CTX-1content in serum, and considerably higher tibia index and tibia calcium content.
                • Relative bioavailability · full text, Section '3.5. ABPs Significantly Improved Calcium':The rates of calcium transport in the ABPs + AB−Ca group were 3.88-, 2.13-, 2.55-, 3.13-, 2.38-, 2.31-, and 2.30-fold greater than those in the NC group, and 1.28-, 1.24-, 1.13-, 1.15-, 1.20-, 1.19-, and 1.19-fold greater than those of the AB−Ca group at 30, 60, 90, 120, 150, 180, and 240 min, respectively.
              • HumanDifferent elemental infant formulas show equivalent phosphorus and calcium bioavailability in healthy volunteers.
                Nutr Res, 2021 · Design: randomized; crossover; double-blind · abstract only (PubMed) · open access (hybrid)
                PMID 33450668DOI 10.1016/j.nutres.2020.11.004
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:The present study aims to evaluate the bioavailability of phosphorus from 2 commercial elemental formulas and to test our hypothesis of bioequivalence of the 2 products in healthy volunteers receiving gastric acid-suppressive medication.
                • Key findings · abstract:Results show that the geometric mean ratio (GMR) and 90% CI for serum phosphate were 1.041 (0.998-1.086) and 1.020 (0.963-1.080) for AUC0-360 and Cpeak, respectively, meeting the predetermined criteria for bioequivalence.
                • Key findings · abstract:Urinary creatinine-corrected phosphate followed a similar pattern after intake of Product A and B, but did not reach bioequivalence crit[excerpt truncated in our database — see source]
                • AUC · abstract:Results show that the geometric mean ratio (GMR) and 90% CI for serum phosphate were 1.041 (0.998-1.086) and 1.020 (0.963-1.080) for AUC0-360 and Cpeak, respectively, meeting the predetermined criteria for bioequivalence.
                • AUC · abstract:Urinary creatinine-corrected phosphate followed a similar pattern after intake of Product A and B, but did not reach bioequivalence criteria (GMR: AUC70-370 = 1.105 (0.918-1.330);
                • AUC · abstract:Serum calcium concentrations (GMR: AUC0-360 = 1.002 (0.996-1.009);
                • AUC · abstract:Cpeak = 0.991 (0.983-0.999)) and urinary creatinine-corrected calcium excretion (GMR: AUC70-370 = 1.117 (1.023-1.219);
                • Food effect · abstract:After a standardized low phosphorus meal followed by overnight fasting, subjects consumed 1 gram of phosphorus in a single oral dose of 1217 kcal of Product A (Neocate) or Product B (Elecare).
              • HumanReference range for 24-h urine calcium, calcium/creatinine ratio, and correlations with calcium absorption and serum vitamin D metabolites in normal women.
                Osteoporos Int, 2021 · Design: stable-isotope · abstract only (PubMed) · open access (green)
                PMID 32886188DOI 10.1007/s00198-020-05615-6PMC8451703 (free full text)
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:UNLABELLED: A study of 959 black and white women shows that the normal range for 24-h urine calcium excretion in white women is 30-300 mg and 10-285 mg in black women.
                • Key findings · abstract:Clinical laboratories use a normal range for 24-h urine calcium excretion of 100-300 mg; there is a need for them to update their age- and race-specific ranges.
                • Key findings · abstract:The objective of this analysis is to define a normal range for young women age 25-45 years and older women age 55-90 years, white and black, for 24-h urine calcium and calcium/creatinine ratio, and to examine the relationship between 24-h urine calcium, calcium absor[excerpt truncated in our database — see source]
              • HumanIntestinal Calcium Absorption.
                Compr Physiol, 2021 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 34058017DOI 10.1002/cphy.c200014
                Verification: abstract-only auto-extract; unverified
                • Key findings · abstract:Other proteins and transporters (e.g., plasma membrane vitamin D receptor and voltage-dependent calcium channels), as well as vesicular calcium transport that probably contributes to intestinal calcium absorption, are also discussed. © 2021 American Physiological Society.
              • HumanRelative bioavailability and pharmacokinetic comparison of calcium glucoheptonate with calcium carbonate.
                Pharmacol Res Perspect, 2020 · Design: randomized; crossover · full text (Europe PMC XML) + abstract · open access (gold)
                PMID 32302064DOI 10.1002/prp2.589PMC7164401 (free full text)
                Verification: full-text auto-extracted verbatim snippets with location; needs human check
                • Key findings · abstract:The objective of this study was to compare the relative oral bioavailability of calcium from calcium glucoheptonate, a highly soluble calcium salt containing 8.2% of elemental calcium, to that of calcium carbonate.
                • Key findings · abstract:The relative oral bioavailability of calcium from calcium glucoheptonate as compared to calcium carbonate was 92% within 6 hours and 89% within 12 hours after study drug administration.
                • Key findings · abstract:The 90% confidence intervals for the mean test/reference ratios of the maximum plasma concentration and the area under the concentration-time curve at 12 hours post-administration were 77.09%-120[excerpt truncated in our database — see source]
                • AUC · abstract:The 90% confidence intervals for the mean test/reference ratios of the maximum plasma concentration and the area under the concentration-time curve at 12 hours post-administration were 77.09%-120.31% and 60.58%-122.30%, respectively.
                • AUC · full text, Section 'Pharmacokinetic findings':The 90% CIs of the ratios (test/reference) for the log‐transformed values of C max and AUC0–t at 6 and 12 hours post‐administration are shown in Table 4.
                • AUC · full text, Section 'Pharmacokinetic findings':At 6 hours after administration of either calcium carbonate or calcium glucoheptonate, the 90% CIs were 78.88%–124.83% and 66.42%–125.22% for the log‐transformed values of C max and AUC0–t, respectively.
                • AUC · full text, TABLE 4:90% confidence interval (CI) ratios of natural logarithm‐transformed pharmacokinetic parameters of calcium glucoheptonate (test drug)/calcium carbonate (reference drug) Parameter Geometric mean ratio – % 90% CIs of the geometric mean ratio (%) Intra‐subject coefficient of variation (%) 6 hours 12 hours 6 hours 12 hours 6 hours 12 hours C max, mg/L 99.23 96.30 78.88‐124.83 77.09‐120.31 45.19 44.90
                • Form comparison · full text, Section 'Pharmacokinetic findings':The relative oral bioavailability (F) of calcium from calcium glucoheptonate as compared to calcium carbonate was 92% within 6 hours and 89% within 12 hours after study drug administration.
              • HumanResponse surface optimization of biocompatible elastic nanovesicles loaded with rosuvastatin calcium: enhanced bioavailability and anticancer efficacy.
                Drug Deliv Transl Res, 2020 · Design: not stated · abstract only (PubMed) · closed/paywalled
                PMID 32394333DOI 10.1007/s13346-020-00761-0
                Verification: abstract-only auto-extract; unverified
                • HumanNovel calcium-chelating peptides from octopus scraps and their corresponding calcium bioavailability.
                  J Sci Food Agric, 2019 · Design: not stated · abstract only (PubMed) · closed/paywalled
                  PMID 29931683DOI 10.1002/jsfa.9212
                  Verification: abstract-only auto-extract; unverified
                  • Key findings · abstract:The particle radius of OSPH increased by 32.25 nm after the calcium chelated with OSPH, indicating intramolecular and intermolecular folding and aggregating.
                  • Key findings · abstract:In particular, OSPH-Ca could protect calcium ions from precipitation caused by dietary inhibitors tannic acid and phytate, while calcium uptake efficiency remained at 3.35 and 1.68 times higher than that of CaCl2 .
                • HumanA pharmacokinetic model of lead absorption and calcium competitive dynamics.
                  Sci Rep, 2019 · Design: not stated · full text (Europe PMC XML) + abstract · open access (gold)
                  PMID 31578386DOI 10.1038/s41598-019-50654-7PMC6775169 (free full text)PDF
                  Verification: full text read; no PK numbers matched
                  • HumanImproving Plasma Stability and Bioavailability In Vivo of Gemcitabine Via Nanoparticles of mPEG-PLG-GEM Complexed with Calcium Phosphate.
                    Pharm Res, 2018 · Design: not stated · abstract only (PubMed) · closed/paywalled
                    PMID 30327887DOI 10.1007/s11095-018-2506-2
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:RESULTS: After incubation in plasma at 37°C for 24 h, gemcitabine was degraded by 24.6% for the mPEG-PLG-GEM, 14.7% for the mPEG-PLG-GEM/CaP nanoparticles, and 90% for the free gemcitabine solution.
                    • Key findings · abstract:It was observed that mPEG-PLG-GEM and mPEG-PLG-GEM/CaP improved the area-under-curve (AUC) values by 5.26-fold and 6.33-fold compared to free drug, respectively.
                    • AUC · abstract:It was observed that mPEG-PLG-GEM and mPEG-PLG-GEM/CaP improved the area-under-curve (AUC) values by 5.26-fold and 6.33-fold compared to free drug, respectively.
                    • Relative bioavailability · abstract:It was observed that mPEG-PLG-GEM and mPEG-PLG-GEM/CaP improved the area-under-curve (AUC) values by 5.26-fold and 6.33-fold compared to free drug, respectively.
                  • HumanEffect of various calcium salts on non-heme iron bioavailability in fasted women of childbearing age.
                    J Trace Elem Med Biol, 2018 · Design: randomized; stable-isotope · n: 27 women · abstract only (PubMed) · open access (green)
                    PMID 29895376DOI 10.1016/j.jtemb.2018.04.029
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:Iron was labeled with the radioisotopes 59Fe or 55Fe, and the absorption of iron was measured by erythrocyte incorporation of radioactive Fe RESULTS: 800 mg of elemental calcium as calcium citrate produced a significant decrease in non-heme iron bioavailability (repeated measures ANOVA, F = 3.79, p = 0.018).
                  • HumanImportance of bioavailable calcium in fluoride dentifrices for enamel remineralization.
                    J Dent, 2018 · Design: randomized; crossover; double-blind · abstract only (PubMed) · not checked (off-topic)
                    PMID 30099066DOI 10.1016/j.jdent.2018.08.005
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:RESULTS: All calcium and fluoride containing toothpastes released > 90% of bioavailable fluoride and were superior to the respective fluoride alone toothpastes in remineralization of enamel subsurface lesions.
                  • HumanCalcium Bioavailability from Mineral Waters with Different Mineralization in Comparison to Milk and a Supplement.
                    J Am Coll Nutr, 2017 · Design: randomized; crossover · n: 21 healthy men · abstract (PubMed); full-text PDF saved · open access (bronze)
                    PMID 28628402DOI 10.1080/07315724.2017.1299651PDF
                    Verification: full-text auto-extracted verbatim snippets with location; needs human check
                    • Key findings · abstract:OBJECTIVE: The aim of the present study was to compare the bioavailability of calcium from 3 mineral waters with different concentrations of minerals with that of milk and a calcium supplement.
                    • Key findings · abstract:Primary outcome variables were the area under the curve of serum calcium levels for 10-hour (AUC0-10h) and 24-hour urinary calcium excretion.
                    • Key findings · abstract:RESULTS: In all groups, no significant differences in the AUC0-10h of serum calcium levels as well as in the 24-hour urinary calcium excretion were observed.
                    • Key findings · abstract:CONCLUSION: Given an equivalent bioavailability of calcium in all test products, neither a high conc[excerpt truncated in our database — see source]
                    • AUC · abstract:Primary outcome variables were the area under the curve of serum calcium levels for 10-hour (AUC0-10h) and 24-hour urinary calcium excretion.
                    • AUC · abstract:RESULTS: In all groups, no significant differences in the AUC0-10h of serum calcium levels as well as in the 24-hour urinary calcium excretion were observed.
                    • AUC · full text, p.2:week wash-out phases in between. Primary outcome variables were the area mineralization; general under the curve of serum calcium levels for 10-hour (AUC0–10h) and 24-hour urinary calcium excretion. nutrition Results: In all groups, no significant differences in the AUC0-10h of serum calcium levels as well as in the 24- hour urinary calcium excretion were observed. Likewise, mean changes in serum p
                    • AUC · full text, p.3:rticipants were Clinical Trial Register (DRKS00010411). allowed to drink water at any time, not exceeding 1 L. The primary outcome variables were the area under the curve (AUC) of serum Ca levels for 10 hours (AUC0-10h) and Subjects the 24-hour urinary Ca excretion [14–16]. Serum concentra- Healthy participants (n D 21) were recruited from the general tions of Ca, phosphate, and parathormone as we
                    • AUC · full text, p.4:388 T. GREUPNER ET AL. Table 2. Area under the Curve (AUC0-10h) Serum Calcium Concentrations Corrected Even in studies with treatments over 3 to 5 days, no significant to Baseline Levels and Urinary Calcium Excretion over 24 Hours after Consumption differences in Ca absorption between mineral wat
                    • Food effect · full text, p.3:ter (12 mg Ca per liter) at defined time points during the 12 hours prior to Twenty-one healthy males and females (men: n D 5, women: the first draw of fasting blood. Test products had to be n D 16) participated in the study. The mean age was 24.1 § 2.6 years and the mean body mass index was 23.1 § 3.3 kg/m2. Due to the crossover design, baseline levels (including 25- Table 1. Mineral composition of
                    • Food effect · full text, p.4:300 mg Ca. for 4 weeks before and during the study to standardize vitamin No significant differences regarding the AUC0-10h of serum Ca D status. The fasting 25-hydroxyvitamin D concentrations of were found between the test products. The general findings are the participants were above 75 nmol/L, which ensured optimal consistent with previous studies showing equivalent Ca absorp- Ca absorption. Thes
                    • Form comparison · full text, p.4:al the following 2 hours, the levels slightly decreased in all groups density and resulted in significantly reduced serum osteocalcin (Fig. 3). levels compared to low-Ca mineral water (80 mg/L of calcium) in postmenopausal women [26]. Vitamin D promotes Ca absorption in the gut by inducing Discussion the synthesis of calbindin and maintaining adequate serum Ca In this randomized crossover study wit
                    • Form comparison · full text, p.5:ith study by Couzy et al. [11] showed a nonsignificant increase magnesium-rich mineral water. of 17% in calciuria with Ca and SO42¡-rich mineral water compared to milk in 9 subjects. Likewise, a longer interven- tion over 3 weeks showed a significantly higher urinary vol- Conclusion ume (ml/day) and a higher urinary Ca excretion with an The results of serum and urine analysis indicated that the bio-
                  • HumanSoluble Corn Fiber Increases Calcium Absorption Associated with Shifts in the Gut Microbiome: A Randomized Dose-Response Trial in Free-Living Pubertal Females.
                    J Nutr, 2016 · Design: randomized; crossover; double-blind; stable-isotope · n: n = 28 · abstract only (PubMed) · open access (bronze)
                    PMID 27281813DOI 10.3945/jn.115.227256
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:BACKGROUND: Soluble corn fiber (SCF; 12 g fiber/d) is shown to increase calcium absorption efficiency, associated with shifts in the gut microbiota in adolescent males and females who participated in a controlled feeding study.
                    • Key findings · abstract:OBJECTIVE: We evaluated the dose response of 0, 10, and 20 g fiber/d delivered by PROMITOR SCF 85 (85% fiber) on calcium absorption, biochemical bone properties, and the fecal microbiome in free-living adolescents.
                    • Key findings · abstract:Stable isotope ((44)Ca and (43)Ca) enrichment in pooled urine was measured by inductively coupled plasma mass spectrometry.
                    • Key findings · abstract:RESULTS: Calcium absorption[excerpt truncated in our database — see source]
                  • HumanDietary calcium impairs tomato lycopene bioavailability in healthy humans.
                    Br J Nutr, 2016 · Design: randomized; crossover · abstract (PubMed); full-text PDF saved · open access (bronze)
                    PMID 28069089DOI 10.1017/S0007114516004335PDF
                    Verification: full-text auto-extracted verbatim snippets with location; needs human check
                    • Key findings · abstract:Plasma LYC concentration was measured at regular time intervals over 7 h postprandially.
                    • Key findings · abstract:LYC bioavailability was diminished by 83 % following the addition of Ca in the test meal.
                    • Food effect · abstract:First, in a randomised, two-way cross-over study, ten healthy adults consumed either a test meal that provided 19-mg (all-E)-LYC from tomato paste or the same meal plus 500-mg calcium carbonate as a supplement.
                    • Food effect · abstract:Plasma LYC concentration was measured at regular time intervals over 7 h postprandially.
                    • Food effect · abstract:LYC bioavailability was diminished by 83 % following the addition of Ca in the test meal.
                    • AUC · full text, p.3:echinenone) reference addition, the postprandial plasma LYC response, as evaluated curves. All solvents used were of HPLC grade (Carlo Erba). by the AUC of the 0–7-h plasma LYC concentration, was significantly lower following consumption of the test meal with added Ca than following consumption of the test meal without Measurement of mixed micelles size and zeta potential added Ca (−83 %, P = 0·047
                    • AUC · full text, p.4:ntrations were baseline adjusted by using the fasting plasma LYC decrease (P = 0·006; data not shown) in LYC bioaccessibility concentration. (b) Mean AUC of the postprandial plasma LYC responses when Ca (1000 mg/l) was added to the model. Thus, differences obtained after intake of either the control or the calcium-supplemented meal. Means were compared by Wilcoxon’s signed-rank test. (c) Individua
                    • Food effect · full text, p.2:bjects arrived at the local Centre from the in vitro experiments was extracted and analysed as for Human Nutrition (Laboratory of Human Nutrition). A fasting described by Gleize et al.(29). In brief, up to 2 ml of the samples blood sample was collected 20 min before administration of the was de-proteinated by adding 1 volume of ethanol, which also meal. The subjects then consumed the test meal wit
                    • Food effect · full text, p.3:medium (Fig. 2(b)). Baseline characteristics of the subjects are shown in Table 1. Nevertheless, there was no dose effect of the concentration of The fasting plasma LYC concentration of the subjects was in the Ca on the zeta potential of mixed micelles. Table 1. Characteristics of the subjects* (Mean values with their standard errors) Discussion Parameters Mean SEM This study was initiated followi
                    • Food effect · full text, p.4:For each subject, postprandial plasma digestion model. We indeed observed a significant 84·7 % LYC concentrations were baseline adjusted by using the fasting plasma LYC decrease (P = 0·006; data not shown) in LYC bioaccessibility concentration. (b) Mean AUC of the postprandial plasma LYC responses when Ca (1000 mg/l) was added to the model. Thus, differences obtained after intake of either the cont
                    • Form comparison · full text, p.5:, or other divalent bioavailability of lycopene when consumed as cis-isomers minerals, on the bioavailability of other carotenoids and from tangerine compared to red tomato juice, a randomized, cross-over clinical trial. Mol Nutr Food Res 59, 658–669. lipophilic micronutrients. 12. Borel P (2003) Factors affecting intestinal absorption of highly lipophilic food microconstituents (fat-soluble vitam
                  • HumanInulin and fructooligosaccharide affect in vitro calcium uptake and absorption from calcium-enriched gluten-free bread.
                    Food Funct, 2016 · Design: not stated · abstract only (PubMed) · closed/paywalled
                    PMID 26965706DOI 10.1039/c6fo00140h
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:In the present study, the in vitro model composed of the intestinal-like Caco-2 cells and the human intestinal bacteria (Lactobacillus, Enterococcus and Enterobacteriaceae) were used to analyse the effect of inulin and fructooligosaccharide (FOS) of different chain lengths, on calcium uptake and absorption from experimental GFB.
                    • Key findings · abstract:Analysed IFs, especially short-chain FOS, significantly (p < 0.05) increased cellular calcium uptake from GFB digest and stimulated the intestinal bacteria applied in the cultures to the intensive synthesis of organic acids.
                  • HumanDietary and pharmacological compounds altering intestinal calcium absorption in humans and animals.
                    Nutr Res Rev, 2015 · Design: not stated · abstract (PubMed); full-text PDF saved · open access (bronze)
                    PMID 26466525DOI 10.1017/S0954422415000050PDF
                    Verification: full-text auto-extracted verbatim snippets with location; needs human check
                    • Relative bioavailability · full text, p.2:erent kinetics. In addition, the tion rate in each intestinal segment. The order of Ca absorption affinity of TRPV5 for the inhibitor ruthenium red is 100-fold that rate is: duodenum > jejunum > ileum(16). Ca absorption in the of TRPV6(32). colon is probably very important in pathological conditions such TRPV6 transcripts have been found in duodenum, but not in as short bowel syndrome(18). ileum, h
                    • Relative bioavailability · full text, p.3:of 3 Na+:1 Ca2+ shown in mice that a single administration of 1,25(OH)2D3 and can function in either a forward mode (Ca2+ extrusion) or in produced a 30-fold maximal increase in the ileal TRPV6 mRNA a reversed mode (Ca2+ entry), depending on the Na+ and Ca at 9 h. Multiple dosing of 1,25(OH)2D3 increased the ileal gradients and the membrane potential(63). We have found that TRPV6 to 200- to 600-fo
                    • Food effect · full text, p.7:ated to increased intestinal Ca absorption. Meyer et al.(143) via a cation exchange mechanism between cellular H+ for have demonstrated that chickens fed a low-P diet displayed an luminal Ca2+ favoured by exchanger activity 2H+/Ca2+(157). Fatty increase in intestinal VDR mRNA. The authors have reported acids would increase the proliferation of colonic epithelial cells, Nutrition Research Reviews t
                    • Food effect · full text, p.9:AP was one of the best candidates to suffer oxidative Coffee stress(206), we later studied the effect of BSO on the activity of this enzyme in chicks fed a commercial diet. In fact, the AP Coffee drinking is a popular habit worldwide. It is consumed in activity declined after BSO treatment, which was dose and time considerable amounts every day. Caffeine, a methylxanthine dependent. The effect occ
                    • Food effect · full text, p.11:reticulum and mitochondria in Replogle et al.(237) have examined eleven inbred lines of cardiac and skeletal muscle – pivotal roles in Ca2+ and mice fed on defined diets containing either high or low Ca reactive oxygen species signaling. J Cell Sci 15, 2965–2978. concentration from weaning to 12 weeks of age. The authors 3. Szadujkis-Szadurska K, Szadujkis-Szadurski R, Szadujkis- Szadurski L, et al
                    • Form comparison · full text, p.1:ible for about 90 % of overall Ca absorption. The longer coordinated work, serum Ca concentration is maintained within residence time in the ileum as compared with the other Abbreviations: 1,25(OH)2D3, 1,25-dihydroxycholecalciferol; Al, aluminium ions; AP, alkaline phosphatase; BMD, bone mineral density; BSO, dl-buthionine- (S,R)-sulfoximine; CB, calbindin; CPP, caseinophosphopeptides; ER, oestrog
                    • Form comparison · full text, p.6:airy products and Ca intake protects activity of intestinal alkaline phosphatase (AP) is concomitantly against the distal colon and rectal tumours as compared with increased by dietary Ca restriction, but a real role of this protein the proximal colon and reduces the risk of colon cancer(116). It in intestinal Ca absorption cannot be discarded(55). Benn is also quite possible that a low Ca intake
                    • Form comparison · full text, p.7:ting that seaweed Ca extract is a good Ca and Mg2+ source for SCFA production by intestinal microbes is responsible for this improving bone health as compared with synthetic Ca2+ and effect, as well as the increase in the caecal mucosa area and the Mg2+ supplementation. soluble Ca concentration(166). https://doi.org/10.1017/S0954422415000050 Published online by Cambridge University Press
                  • HumanCalcium carbonate does not affect imatinib pharmacokinetics in healthy volunteers.
                    Cancer Chemother Pharmacol, 2014 · Design: randomized; crossover · abstract only (PubMed) · open access (PMC)
                    PMID 24170263DOI 10.1007/s00280-013-2337-0PMC3880632 (free full text)
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:Plasma concentrations of imatinib and its active N-desmethyl metabolite CGP74588 were assayed by LC-MS; data were analyzed non-compartmentally and compared after log transformation.
                    • Key findings · abstract:RESULTS: Calcium carbonate administration did not significantly affect the imatinib area under the plasma concentration versus time curve (AUC) (41.2 μg/mL h alone vs. 40.8 μg/mL h with calcium carbonate, P = 0.99), maximum plasma concentration (C(max)) (2.35 μg/mL alone vs. 2.39 μg/mL with calcium carbonate, P = 0.89).
                    • Cmax · abstract:RESULTS: Calcium carbonate administration did not significantly affect the imatinib area under the plasma concentration versus time curve (AUC) (41.2 μg/mL h alone vs. 40.8 μg/mL h with calcium carbonate, P = 0.99), maximum plasma concentration (C(max)) (2.35 μg/mL alone vs. 2.39 μg/mL with calcium carbonate, P = 0.89).
                    • AUC · abstract:RESULTS: Calcium carbonate administration did not significantly affect the imatinib area under the plasma concentration versus time curve (AUC) (41.2 μg/mL h alone vs. 40.8 μg/mL h with calcium carbonate, P = 0.99), maximum plasma concentration (C(max)) (2.35 μg/mL alone vs. 2.39 μg/mL with calcium carbonate, P = 0.89).
                  • HumanA comparative study of calcium absorption following a single serving administration of calcium carbonate powder versus calcium citrate tablets in healthy premenopausal women.
                    Food Nutr Res, 2014 · Design: crossover · full text (Europe PMC XML) + abstract · open access (gold)
                    PMID 24772062DOI 10.3402/fnr.v58.23229PMC3999951 (free full text)PDF
                    Verification: full-text auto-extracted verbatim snippets with location; needs human check
                    • Key findings · abstract:DESIGN: A two-period, crossover bioavailability study of a single serving of calcium citrate tablets (two tablets=500 mg calcium) versus a single serving of calcium carbonate powder (one packet of powder=1,000 mg calcium) was performed in healthy women aged between 25 and 45.
                    • Key findings · abstract:Results showed that administration of a single serving of a calcium carbonate powder resulted in greater absorption in total and ionized calcium versus a single serving of calcium citrate tablets at 4 h (4.25±0.21 vs. 4.16±0.16, p=0.001).
                    • Food effect · abstract:All subjects were on a calcium-restricted diet 7 days prior to testing and fasted for 12 h before being evaluated at 0, 1, 2, and 4 h after oral administration of the test agents.
                    • AUC · full text, Section 'Serum calcium':This was also demonstrated after calcium carbonate administration versus calcium citrate administration at all time points (1, 2, and 4 h, [p=0.0056, p=0.0001, p=0.001]), AUC 1 (at 1 h), AUC 2 (at 2 h), and AUC 3 (at 4 h) (Fig. 1 and Table 1).
                    • Form comparison · full text, Section 'Serum calcium':This was also demonstrated after calcium carbonate administration versus calcium citrate administration at all time points (1, 2, and 4 h, [p=0.0056, p=0.0001, p=0.001]), AUC 1 (at 1 h), AUC 2 (at 2 h), and AUC 3 (at 4 h) (Fig. 1 and Table 1).
                    • Form comparison · full text, Section 'Serum iPTH':Figure 3 demonstrates the response curve of serum iPTH from baseline to 4 h following calcium carbonate administration versus calcium citrate administration.
                  • HumanVitamin D does not increase calcium absorption in young women: a randomized clinical trial.
                    J Bone Miner Res, 2014 · Design: randomized; double-blind; stable-isotope · abstract only (PubMed) · open access (bronze)
                    PMID 24166866DOI 10.1002/jbmr.2121
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:A total of 198 white and African American women, aged 25 to 45 years, with vitamin D insufficiency, serum 25-hydroxyvitamin D (25OHD) <20 ng/mL, were randomized in a double-blind study to vitamin D3 400, 800, 1600, 2400 IU, or placebo.
                    • Key findings · abstract:Calcium absorption was measured at baseline and after 12 months using a single isotope method with radiocalcium45 and 100 mg of calcium.
                    • Key findings · abstract:Mean baseline serum 25OHD was 13.4 ng/mL (33.5 nmol/L) and increased to 40 ng/mL (100 nmol/L) on the highest dose of 2400 IU.
                    • Key findings · abstract:Using a multivariate regression analysis with significant predictors, baseline absorption, calc[excerpt truncated in our database — see source]
                  • HumanVitamin D supplementation increases calcium absorption without a threshold effect.
                    Am J Clin Nutr, 2014 · Design: randomized; double-blind; stable-isotope · abstract only (PubMed) · open access (bronze)
                    PMID 24335055DOI 10.3945/ajcn.113.067199
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:OBJECTIVE: The objective was to determine whether there is a threshold beyond which increasing doses of vitamin D, or concentrations of serum 25-hydroxyvitamin D [25(OH)D], no longer increase calcium absorption.
                    • Key findings · abstract:The technique of dual isotopes of stable calcium was used with a calcium carrier to measure calcium absorption at baseline and after 8 wk.
                    • Key findings · abstract:The mean calcium intake was 1142 ± 509 mg/d and serum 25(OH)D was 63 ± 14 nmol/L at baseline.
                    • Key findings · abstract:A statistically significant linear trend of an increase in calcium absorption adjusted for age and body mass index with increasing vitamin D₃ dose or[excerpt truncated in our database — see source]
                  • HumanFactors associated with calcium absorption in postmenopausal women: a post hoc analysis of dual-isotope studies.
                    J Acad Nutr Diet, 2014 · Design: stable-isotope · n: n=19 · abstract only (PubMed) · open access (bronze)
                    PMID 24209888DOI 10.1016/j.jand.2013.07.041PMC3989396 (free full text)
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:Variables included subjects' age, race, body mass index, serum calcium, creatinine, parathyroid hormone, 1,25-dihydroxyvitamin D, 25-hydroxyvitamin D, and habitual intake of kilocalories, protein, fat, carbohydrate, fiber, calcium, iron, magnesium, oxalate, phosphorus, potassium, and vitamin D based on outpatient diet diaries.
                    • Key findings · abstract:In multiple variable models predicting net calcium absorption, dietary intake of kilocalories, fat, fiber, calcium, potassium, and serum 1,25-dihydroxyvitamin D were significant.
                    • Key findings · abstract:The square of the correlation between actual and predicted values (an approximation of R[excerpt truncated in our database — see source]
                  • HumanCalcium bioavailability of calcium L-threonate in healthy Chinese subjects measured with stable isotopes (⁴⁴Ca and ⁴²Ca).
                    Eur J Clin Pharmacol, 2013 · Design: stable-isotope · abstract only (PubMed) · closed/paywalled
                    PMID 23229796DOI 10.1007/s00228-012-1420-5
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:The calcium bioavailability was estimated by calculating the true fractional calcium absorption (TFCA) using the abundance ratios of (44)Ca/(40)Ca and (42)Ca/(40)Ca.
                    • Key findings · abstract:RESULTS: The bioavailability of calcium L-threonate in 14 healthy Chinese subjects was 26.49 ± 9.39 %.
                    • Key findings · abstract:The TFCA of the subjects did not statistically correlate with total urinary calcium excretion (0-48 h).
                  • HumanSuperior calcium bioavailability of effervescent potassium calcium citrate over tablet formulation of calcium citrate after Roux-en-Y gastric bypass.
                    Surg Obes Relat Dis, 2013 · Design: randomized; crossover · n: 15 patients · abstract only (PubMed) · closed/paywalled
                    PMID 22222299DOI 10.1016/j.soard.2011.11.011
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:To test the hypothesis that effervescent (liquid) potassium-calcium-citrate (PCC) might be more bioavailable than a tablet formulation of calcium citrate (Citracal Petite), the present study compared a single dose response of the 2 compounds.
                    • Key findings · abstract:METHODS: A total of 15 patients who had undergone Roux-en-Y gastric bypass were included in a 2-phase, crossover, randomized study comparing the single-dose bioavailability of PCC versus Citracal Petite.
                    • Key findings · abstract:Sequential serum and urine samples were collected for a 6-hour period after the dose and analyzed for calcium, parathyroid hormone, and acid-base par[excerpt truncated in our database — see source]
                    • AUC · abstract:The peak to baseline variation and increment in serum calcium (area under the curve) were significantly greater after PCC (P = .015 and P = .002, respectively).
                  • HumanCalcium carbonate does not affect nilotinib pharmacokinetics in healthy volunteers.
                    Cancer Chemother Pharmacol, 2013 · Design: randomized; crossover · abstract only (PubMed) · open access (green)
                    PMID 24036846DOI 10.1007/s00280-013-2283-xPMC3818249 (free full text)
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:Calcium supplementation did not significantly affect nilotinib pharmacokinetic parameters including area under the plasma concentration versus time curve (18.4 μg/mL h alone vs. 16.9 μg/mL h with calcium carbonate, p = 0.83; 80 % power); maximum plasma concentration (C(max)) (0.670 μg/mL alone vs. 6.18 μg/mL with calcium carbonate, p = 0.97); or half-life (18.9 h alone vs. 17.2 h with calcium carbonate, p = 0.18).
                    • Cmax · abstract:Calcium supplementation did not significantly affect nilotinib pharmacokinetic parameters including area under the plasma concentration versus time curve (18.4 μg/mL h alone vs. 16.9 μg/mL h with calcium carbonate, p = 0.83; 80 % power); maximum plasma concentration (C(max)) (0.670 μg/mL alone vs. 6.18 μg/mL with calcium carbonate, p = 0.97); or half-life (18.9 h alone vs. 17.2 h with calcium carbonate, p = 0.18).
                    • AUC · abstract:Calcium supplementation did not significantly affect nilotinib pharmacokinetic parameters including area under the plasma concentration versus time curve (18.4 μg/mL h alone vs. 16.9 μg/mL h with calcium carbonate, p = 0.83; 80 % power); maximum plasma concentration (C(max)) (0.670 μg/mL alone vs. 6.18 μg/mL with calcium carbonate, p = 0.97); or half-life (18.9 h alone vs. 17.2 h with calcium carbonate, p = 0.18).
                  • HumanGalacto-oligosaccharides increase calcium absorption and gut bifidobacteria in young girls: a double-blind cross-over trial.
                    Br J Nutr, 2013 · Design: randomized; stable-isotope · abstract (PubMed); full-text PDF saved · open access (bronze)
                    PMID 23507173DOI 10.1017/S000711451300055XPDF
                    Verification: full-text auto-extracted verbatim snippets with location; needs human check
                    • Key findings · abstract:Fractional Ca absorption was determined from urinary Ca excretion over 48 h at the end of each 3-week period using a dual stable isotope method.
                    • Key findings · abstract:Fractional Ca absorption after the 48 h treatment with control, 5 and 10 g GOS/d was 0·393 (SD 0·092), 0·444 (SD 0·086) and 0·419 (SD 0·099), respectively.
                    • Key findings · abstract:Significant improvements in Ca absorption were seen with both low and high doses of GOS compared with the control (P,0·02), but itwas not a dose-response relationship.
                    • Key findings · abstract:The increase in absorption was greatest in the urine collected after 24 h, which is consistent with lower gut absorption.
                    • Key findings · abstract:T[excerpt truncated in our database — see source]
                    • Relative bioavailability · full text, p.4:t to Purdue into the pGEM-T easy vector (Promega). Standard curves were at the end of each of the three different GOS treatment tests. generated from 10-fold serial dilutions of plasmid DNA. Gene Subjects who did not defecate during any of their clinical copy numbers were calculated based on total DNA and the visits were excluded from this part of the study. In total, percentage of bifidobacteria
                    • Fractional absorption · full text, p.3:The counsellor:participant Ingredients 0 g GOS 2·5 g GOS 5·0 g GOS ratio was 1:3. Whole milk 59 59 59 Water 2·2 3·0 3·4 Pectin slurry* 13·1 13·4 13·7 Fractional calcium absorption Sucrose 3·0 3·0 3·0 Maize syrup 18·5 11·5 5·0 Following an overnight fast, participants provided a rising GOS syrup (Vivinalw GOS)† 0·0 5·9 11·7 urine collection, followed by a fasting collection, on Saturday Ca 2·9 2·9
                    • Fractional absorption · full text, p.4:was used to calculated with an a error of 0·05 and 80 % power to detect determine the quality and quantity of PCR products before a difference in Ca absorption of 5·9 %, assuming a standard loading in equivalent quantities in DGGE gels. DGGE deviation of 2·9 (SD 9·6) %(30). (DCodee Universal Mutation Detection System; Bio-Rad Lab- To explore the effects of usual Ca absorption on the oratories) was
                    • Fractional absorption · full text, p.5:entify major contributors to the variation n 31 in fingerprints. Quantitative PCR results for bifidobacteria Withdrawals were compared independent of fractional absorption to look n4 for treatment effects. This separate analysis was needed Four dropouts Randomised phase 2 because faecal samples could not be collected in 12 h time n 27 intervals like urine. A general linear model including Withdraw
                    • Food effect · full text, p.2:en associated with prebiotic down in the Declaration of Helsinki, and all procedures invol- consumption resulting in caecal hypertrophy(6,7). In rats fed ving human subjects were approved by the Institutional GOS diets, increased crypt depth and cell density in the Review Board of Purdue University. Written informed consent proximal and distal colon were observed(8). was obtained from all subjects
                    • Food effect · full text, p.3:yrup 18·5 11·5 5·0 Following an overnight fast, participants provided a rising GOS syrup (Vivinalw GOS)† 0·0 5·9 11·7 urine collection, followed by a fasting collection, on Saturday Ca 2·9 2·9 2·9 Citric acid 0·9 0·9 0·9 morning. After these initial urine collections, a stable Ca iso- Strawberry flavour and red colour 0·4 0·4 0·4 tope, 44Ca (15 mg), was given orally with a standardised Total 100 1
                    • Food effect · full text, p.8:haride feeding(10), presumably 0·300 through the down-regulation of the vitamin D endocrine system. Perhaps the independent bone effects seen in rats fed soluble fibres are the result of adaptation of the vitamin 0·250 D system after 12 weeks of treatment. Effects on bone changes 0 10 20 30 40 50 60 are not available in the present study cohort as bone measures Time (h) were only assessed at basel
                    • Form comparison · full text, p.1:0·092), 0·444 (SD 0·086) and 0·419 (SD 0·099), respectively. Significant improvements in Ca absorption were seen with both low and high doses of GOS compared with the control (P, 0·02), but it was not a dose – response relationship. The increase in absorption was greatest in the urine collected after 24 h, which is consistent with lower gut absorption. Faecal bifidobacteria increased (control 10·8
                    • Form comparison · full text, p.2:bsorption methane producers, who lack or have a lower number of fraction is up-regulated during pubertal growth, yet other sulphate-reducing bacteria compared with non-methanogenic prebiotics including fructo-oligosaccharides enhance Ca individuals(18). Each phase was separated by a 2-week period absorption efficiency during this life stage(16). to washout any effect of the intervention on gut col
                    • Form comparison · full text, p.6:ional Ca absorption (Fig. 3). greater in subjects consuming the 5 g/d of GOS treatment Ca absorption peaked in the 24 – 36 h urine aliquot, resulting compared with the control and 10 g/d of GOS treatments. in significantly greater absorption than the earlier time The total bacterial copies were only significantly different points. Fractional Ca absorption remained elevated in the when expressed as
                  • HumanCalcium absorption response to cholecalciferol supplementation in hemodialysis.
                    Clin J Am Soc Nephrol, 2013 · Design: clinical trial · n: 30 participants · abstract only (PubMed) · not checked (off-topic)
                    PMID 23411428DOI 10.2215/CJN.08610812PMC3675848 (free full text)
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:DESIGN, SETTING, PARTICIPANTS, & MEASUREMENTS: Paired calcium absorption tests were done before and after 12-13 weeks of 20,000 IU weekly cholecalciferol supplementation in 30 participants with stage 5 CKD on hemodialysis.
                    • Key findings · abstract:Calcium absorption was tested with a standardized meal containing 300 mg calcium carbonate intrinsically labeled with (45)Ca; 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were measured.
                    • Key findings · abstract:The median baseline calcium absorption was 12% (7%-17%) and 12% (7%-16%) at the end of study.
                    • Key findings · abstract:CONCLUSIONS: Patients with stage 5 CKD on hemodialysis had very low calcium absorption v[excerpt truncated in our database — see source]
                    • Food effect · abstract:Calcium absorption was tested with a standardized meal containing 300 mg calcium carbonate intrinsically labeled with (45)Ca; 25-hydroxyvitamin D and 1,25-dihydroxyvitamin D were measured.
                  • HumanA randomized, open-label, 5-period, balanced crossover study to evaluate the relative bioavailability of eltrombopag powder for oral suspension (PfOS) and tablet formulations and the effect of a high-calcium meal on eltrombopag pharmacokinetics when administered with or 2 hours before or after PfOS.
                    Clin Ther, 2012 · Design: randomized; crossover · n: 11 subjects · abstract only (PubMed) · closed/paywalled
                    PMID 22336488DOI 10.1016/j.clinthera.2012.01.011
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:Noncompartmental pharmacokinetic parameters were estimated from plasma concentration-time data collected over 72 hours post-dose.
                    • Key findings · abstract:Plasma eltrombopag AUC(0-∞) was higher for the PfOS than the tablet (geometric least-squares mean ratio [GMR]: 1.22; 90% CI: 1.08-1.38).
                    • Key findings · abstract:Plasma eltrombopag AUC(0-∞) was reduced when the PfOS was administered with a high-calcium meal (GMR: 0.25; 90% CI: 0.224-0.287) or 2 hours after a meal (GMR: 0.53; 90% CI: 0.470-0.601), and, to a lesser extent, when administered 2 hours before a meal (GMR: 0.80; 90% CI: 0.711-0.908).
                    • Key findings · abstract:CONCLUSIONS: In a healthy adult volunteer[excerpt truncated in our database — see source]
                    • Tmax · abstract:T(max) was delayed 1 hour when the PfOS was dosed with a high-calcium meal.
                    • AUC · abstract:Plasma eltrombopag AUC(0-∞) was higher for the PfOS than the tablet (geometric least-squares mean ratio [GMR]: 1.22; 90% CI: 1.08-1.38).
                    • AUC · abstract:Plasma eltrombopag AUC(0-∞) was reduced when the PfOS was administered with a high-calcium meal (GMR: 0.25; 90% CI: 0.224-0.287) or 2 hours after a meal (GMR: 0.53; 90% CI: 0.470-0.601), and, to a lesser extent, when administered 2 hours before a meal (GMR: 0.80; 90% CI: 0.711-0.908).
                    • Food effect · abstract:METHODS: In this single-dose, open-label, randomized-sequence, crossover study, healthy subjects received 25 mg eltrombopag orally as a tablet fasted and as PfOS fasted or with, 2 hours before, or 2 hours after a high-calcium meal.
                    • Food effect · abstract:Plasma eltrombopag AUC(0-∞) was reduced when the PfOS was administered with a high-calcium meal (GMR: 0.25; 90% CI: 0.224-0.287) or 2 hours after a meal (GMR: 0.53; 90% CI: 0.470-0.601), and, to a lesser extent, when administered 2 hours before a meal (GMR: 0.80; 90% CI: 0.711-0.908).
                    • Food effect · abstract:T(max) was delayed 1 hour when the PfOS was dosed with a high-calcium meal.
                  • HumanPharmacokinetics and pharmacodynamics of calcium-vitamin D(3) chewable tablets: a single-blind, multiple-dose study in postmenopausal women.
                    Expert Opin Drug Metab Toxicol, 2011 · Design: not stated · abstract only (PubMed) · closed/paywalled
                    PMID 21635154DOI 10.1517/17425255.2011.591378
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:OBJECTIVE: The objective of this study is to investigate the effect of a newly developed calcium carbonate-vitamin D₃ chewable tablet formulation (600 mg of calcium + 400 IU of vitamin D₃) on serum/urine calcium and serum parathyroid hormone (PTH) as measures of intestinal calcium absorption compared to a placebo.
                    • Key findings · abstract:Total urinary calcium excretion (Ae(0-24 h)) and AUC(0-6 h) for serum calcium were the primary outcome variables and were compared between treatments using a paired sample t-test.
                    • Key findings · abstract:RESULTS: Ae(0-24 h) increased by 42% (uncorrected, p = 0.0001) and 30% (creatinine-corrected, p = 0.
                    • AUC · abstract:Total urinary calcium excretion (Ae(0-24 h)) and AUC(0-6 h) for serum calcium were the primary outcome variables and were compared between treatments using a paired sample t-test.
                    • AUC · abstract:RESULTS: Ae(0-24 h) increased by 42% (uncorrected, p = 0.0001) and 30% (creatinine-corrected, p = 0.0001), after intake, compared with the placebo; serum calcium exposure (AUC(0-6 h)) was also, statistically, significantly greater.
                    • AUC · abstract:PTH, in serum, decreased by 28% (AUC(0-6 h), p = 0.0001) and 14% (AUC(0-24 h), p = 0.0009) when compared with the placebo.
                    • Food effect · abstract:The subjects fasted until 6 h post-dosing.
                  • HumanDo proton pump inhibitors decrease calcium absorption?
                    J Bone Miner Res, 2010 · Design: stable-isotope · full text (Europe PMC XML) + abstract · open access (bronze)
                    PMID 20578215DOI 10.1002/jbmr.166PMC3179281 (free full text)
                    Verification: full-text auto-extracted verbatim snippets with location; needs human check
                    • Key findings · abstract:Two FCA studies were performed 1 month apart to establish baseline calcium absorption.
                    • Key findings · abstract:Multiple linear regression revealed that age, gastric pH, serum omeprazole levels, adherence to omeprazole, and 25-hydroxyvitamin D levels were unrelated to changes in FCA between study visits 2 and 3.
                    • Food effect · abstract:Each participant consumed the same foods during all FCA studies; study meals replicated subjects' dietary habits based on 7-day diet diaries.
                    • Food effect · full text, Table 1:absorption methodology Result Serfaty-Lacrosniere, 1995(12) 13 healthy adults, median age 59 years Omeprazole 40 mg daily for 7 days Calcium consumed with a meal, absorption determined by intestinal lavage No difference in calcium absorption between treatment groups; calcium absorption not altered in all subjects following gastric infusion of 120 mL 0.1 M hydrochloric acid Graziani, 1995(14) 8 hea
                    • Food effect · full text, Section 'Results':Through the combination of dietary and supplemental intake, subjects ingested 1400 ± 650 mg of calcium per day, approximately half (46%) consumed with breakfast.
                  • HumanInhibiting gastric acid production does not affect intestinal calcium absorption in young, healthy individuals: a randomized, crossover, controlled clinical trial.
                    J Bone Miner Res, 2010 · Design: randomized; crossover; double-blind; stable-isotope · abstract only (PubMed) · open access (bronze)
                    PMID 20499372DOI 10.1002/jbmr.108PMC3312746 (free full text)
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:Neither calcium absorption (PPI 34.2% +/- 2.4%, placebo 31.5% +/- 2.1%, p = .24) nor urinary calcium (PPI 321 +/- 38 mg/34 hours, placebo 355 +/- 37 mg/34 hours, p = .07) differed between the PPI and placebo groups.
                  • HumanFructo-oligosaccharides and calcium absorption and retention in adolescent girls.
                    J Am Coll Nutr, 2010 · Design: randomized; crossover; double-blind · abstract only (PubMed) · closed/paywalled
                    PMID 21041813DOI 10.1080/07315724.2010.10719855
                    Verification: abstract-only auto-extract; unverified
                    • Key findings · abstract:OBJECTIVES: This study was designed to evaluate the effect of 9 g/d of fructo-oligosaccharides as part of a controlled diet on calcium absorption and retention in adolescent girls.
                    • Key findings · abstract:On day 14 of the diet period, fractional calcium absorption was determined from the enrichment of (44)Ca in 4-day urine collections.
                    • Key findings · abstract:RESULTS: Calcium absorption (67 ± 3 vs. 66 ± 3%) and retention (409 ± 394 vs. 464 ± 241 mg/d) were not significantly different when diets contained 9 g/d oligofructose-enriched inulin or not in a calcium-fortified cereal.
                  • HumanProton pump inhibitor suppression of calcium absorption presenting as respiratory distress in a patient with bilateral laryngeal paralysis and hypocalcemia.
                    Ear Nose Throat J, 2010 · Design: not stated · abstract only (PubMed) · unknown
                    PMID 20155676
                    Verification: abstract-only auto-extract; unverified
                    • HumanComparison of the absorption of calcium carbonate and calcium citrate after Roux-en-Y gastric bypass.
                      Obes Surg, 2009 · Design: randomized; crossover; double-blind · abstract only (PubMed) · open access (green)
                      PMID 19437082DOI 10.1007/s11695-009-9850-6PMC4469176 (free full text)
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:Calcium citrate resulted in a significantly higher serum C (max) (9.4 + 0.4 mg/dl vs. 9.2 + 0.3 mg/dl, p = 0.02) and serum AUC (55 + 2 mg/dl vs. 54 + 2 mg/dl, p = 0.02).
                      • Key findings · abstract:Calcium citrate resulted in a significantly lower PTH(min) (24 + 11 pg/ml vs. 30 + 13 pg/ml, p = 0.01) and a higher AUC (-32 + 51 pg/ml vs. -3 + 56 pg/ml, p = 0.04).
                      • Key findings · abstract:There was a non-significant trend for higher urinary AUC in the calcium citrate group (76.13 + 36.39 mg/6 h vs. 66.04 + 40.82, p = 0.17).
                      • Cmax · abstract:Calcium citrate resulted in a significantly higher serum C (max) (9.4 + 0.4 mg/dl vs. 9.2 + 0.3 mg/dl, p = 0.02) and serum AUC (55 + 2 mg/dl vs. 54 + 2 mg/dl, p = 0.02).
                      • AUC · abstract:Calcium citrate resulted in a significantly higher serum C (max) (9.4 + 0.4 mg/dl vs. 9.2 + 0.3 mg/dl, p = 0.02) and serum AUC (55 + 2 mg/dl vs. 54 + 2 mg/dl, p = 0.02).
                      • AUC · abstract:Calcium citrate resulted in a significantly lower PTH(min) (24 + 11 pg/ml vs. 30 + 13 pg/ml, p = 0.01) and a higher AUC (-32 + 51 pg/ml vs. -3 + 56 pg/ml, p = 0.04).
                      • AUC · abstract:There was a non-significant trend for higher urinary AUC in the calcium citrate group (76.13 + 36.39 mg/6 h vs. 66.04 + 40.82, p = 0.17).
                    • HumanMeals and dephytinization affect calcium and zinc absorption in Nigerian children with rickets.
                      J Nutr, 2009 · Design: randomized; stable-isotope · abstract only (PubMed) · open access (bronze)
                      PMID 19321589DOI 10.3945/jn.108.101030PMC2714392 (free full text)
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:After 6 wk, calcium and zinc absorption were measured in both groups with and without maize porridge using stable isotopes.
                      • Key findings · abstract:Calcium absorption was greater with a meal (61.3 +/- 25.1%) than without (27.8 +/- 14.6%;[excerpt truncated in our database — see source]
                      • Key findings · abstract:Zinc absorption was lower with a meal (16.2 +/- 8.0%) than without (63.4 +/- 23.9%;[excerpt truncated in our database — see source]
                      • Key findings · abstract:Enzymatic dephytinization increased relative zinc absorption from a meal by 101 +/- 81% (P < 0.001) but did not affect calcium absorption.
                      • Food effect · abstract:Calcium absorption was greater with a meal (61.3 +/- 25.1%) than without (27.8 +/- 14.6%;
                      • Food effect · abstract:Zinc absorption was lower with a meal (16.2 +/- 8.0%) than without (63.4 +/- 23.9%;
                      • Food effect · abstract:Enzymatic dephytinization increased relative zinc absorption from a meal by 101 +/- 81% (P < 0.001) but did not affect calcium absorption.
                    • HumanCopper and calcium uptake in colored hair.
                      J Cosmet Sci, 2009 · Design: not stated · abstract only (PubMed) · unknown
                      PMID 19586601
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:The increased uptake of these metals can have a detrimental impact on fiber properties-for example, reducing shine and causing a poor wet and dry feel (3).
                      • Key findings · abstract:In addition, the increased uptake of copper can also contribute to further fiber damage during subsequent coloring due to its ability to take part in metal-induced radical chemistry (4).
                      • Key findings · abstract:Images with up to 50-nm spatial resolution of the preferential locations of calcium uptake were obtained, showing a high concentration of calcium in the cuticle region of colored hair, specifically in the sulfur-rich regions (A-layer and exocuticle).
                    • HumanPharmacokinetics of calcium from calcium supplements in healthy volunteers.
                      Pak J Pharm Sci, 2008 · Design: randomized; crossover · abstract only (PubMed) · unknown
                      PMID 18390439
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:The preparations were compared using pharmacokinetic parameters such as the area under the plasma concentration - time curve AUC((0-11)), peak plasma concentration C(max), time to reach maximum plasma concentration T(max).
                      • Key findings · abstract:No statistically significant difference was observed for any of the parameters, and the 90% confidence intervals calculated for the ratio of the logarithmically transformed AUC((0-11)) values of both formulations were within the bioequivalence limit of 0.80-1.25.
                      • Cmax · abstract:The preparations were compared using pharmacokinetic parameters such as the area under the plasma concentration - time curve AUC((0-11)), peak plasma concentration C(max), time to reach maximum plasma concentration T(max).
                      • Tmax · abstract:The preparations were compared using pharmacokinetic parameters such as the area under the plasma concentration - time curve AUC((0-11)), peak plasma concentration C(max), time to reach maximum plasma concentration T(max).
                      • AUC · abstract:The preparations were compared using pharmacokinetic parameters such as the area under the plasma concentration - time curve AUC((0-11)), peak plasma concentration C(max), time to reach maximum plasma concentration T(max).
                      • AUC · abstract:No statistically significant difference was observed for any of the parameters, and the 90% confidence intervals calculated for the ratio of the logarithmically transformed AUC((0-11)) values of both formulations were within the bioequivalence limit of 0.80-1.25.
                    • HumanCalcium absorption from commonly consumed vegetables in healthy Thai women.
                      J Food Sci, 2008 · Design: randomized; crossover · abstract only (PubMed) · closed/paywalled
                      PMID 19021804DOI 10.1111/j.1750-3841.2008.00949.x
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:The absorbability of calcium from ivy gourd, a green leafy vegetable (Coccinia grandix Voigt.) and winged bean young pods (Psophocarpus tetragonolobus [L] DC) were measured in 19 healthy adult women aged 20 to 45 y, in a 3-way, randomized-order, crossover design with an average calcium load of 100 mg and milk as the referent.
                      • Key findings · abstract:Absorption of calcium was determined on a blood sample drawn 5 h after ingestion of the test meal.
                      • Key findings · abstract:Fractional calcium absorption (X+/- SD) was 0.391 +/- 0.128 from winged beans, 0.476 +/- 0.109 from ivy gourd, and 0.552 +/- 0.119 from milk.
                      • Key findings · abstract:The difference in fractio[excerpt truncated in our database — see source]
                      • Food effect · abstract:The test meals were extrinsically labeled with 44Ca and given with rice as breakfast after an overnight fast.
                      • Food effect · abstract:Absorption of calcium was determined on a blood sample drawn 5 h after ingestion of the test meal.
                    • HumanCalcium bioavailability of nanonized pearl powder for adults.
                      J Food Sci, 2008 · Design: not stated · abstract only (PubMed) · closed/paywalled
                      PMID 19021809DOI 10.1111/j.1750-3841.2008.00965.x
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:The bioavailability was evaluated by the serum total calcium increment, the serum intact parathyroid hormone (iPTH) reduction, and the urine calcium/creatinine ratio increment in 6 h after administration.
                    • HumanCalcium absorption is not increased by caseinophosphopeptides.
                      Am J Clin Nutr, 2006 · Design: randomized; crossover; stable-isotope · n: 15 adults · abstract only (PubMed) · open access (bronze)
                      PMID 16825691DOI 10.1093/ajcn/84.1.162
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:DESIGN: A randomized crossover trial was undertaken in 15 adults in whom we measured the absorption of calcium from a calcium lactate drink (drink A: 400 mg Ca as lactate) and 2 preparations enriched with forms of CPP (1.7 g each; drinks B and C).
                      • Key findings · abstract:RESULTS: The quantity of calcium absorbed was significantly lower from drink A (103 mg) than from drink B (117 mg;[excerpt truncated in our database — see source]
                      • Key findings · abstract:However, because the CPP preparations contributed additional calcium besides that found in the calcium lactate (drink A), fractional absorption of calcium from drink B (23%) was slightly but significantly (P = 0.015) lower than that[excerpt truncated in our database — see source]
                      • Fractional absorption · abstract:RESULTS: The quantity of calcium absorbed was significantly lower from drink A (103 mg) than from drink B (117 mg;
                      • Fractional absorption · abstract:However, because the CPP preparations contributed additional calcium besides that found in the calcium lactate (drink A), fractional absorption of calcium from drink B (23%) was slightly but significantly (P = 0.015) lower than that from drink A (26%).
                    • Human[Bioavailability of dietary calcium].
                      Arq Bras Endocrinol Metabol, 2006 · Design: not stated · abstract (PubMed); full-text PDF saved · open access (gold)
                      PMID 17160208DOI 10.1590/s0004-27302006000500005PDF
                      Verification: full-text auto-extracted verbatim snippets with location; needs human check
                      • Form comparison · full text, p.5:mente 30%. Quando esses Ca foi significantemente mais alta para a fórmula con- dois alimentos, com biodisponibilidades diferentes, tendo lactose (48% vs. 33%, p< 0,01) (32). Estes acha- são ingeridos juntos durante a mesma refeição, a fração dos sugerem que a absorção de Ca em crianças é mais de absorção de Ca a partir do leite diminui em 30% alta nas fórmulas infantis à base de soja contendo lac-
                      • Form comparison · full text, p.8:cloridria em pouco solúvel, os controles absorveram muito mais Ca idosos, endógena ou iatrogênica, não afeta a absorção do que os com acloridria (23% vs. 4%). Por outro lado, Ca da dieta, mesmo na presença de fibras. quando foi usado o citrato, mais solúvel, os com Embora os estudos citados possam ser alvo de acloridria inesperadamente absorveram Ca quase duas críticas do ponto de vista de seleção
                    • HumanCalcium retention in adolescent boys on a range of controlled calcium intakes.
                      Am J Clin Nutr, 2006 · Design: randomized; crossover · abstract only (PubMed) · open access (bronze)
                      PMID 16895892DOI 10.1093/ajcn/84.1.414
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:After a 1-wk equilibration period, calcium retention was calculated as dietary calcium intake minus the calcium excreted in the feces and urine over the following 2 wk.
                      • Key findings · abstract:RESULTS: Maximal calcium retention in boys was achieved at an intake of 1140 mg/d.
                      • Key findings · abstract:Calcium retention was higher (by 171 +/- 38 mg/d) in boys than in girls at all calcium intakes studied.
                    • HumanTrue fractional calcium absorption is decreased after Roux-en-Y gastric bypass surgery.
                      Obesity (Silver Spring), 2006 · Design: stable-isotope · n: 21 women · abstract only (PubMed) · open access (green)
                      PMID 17135609DOI 10.1038/oby.2006.226PMC4016232 (free full text)
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:RESEARCH METHODS AND PROCEDURES: We recruited 25 extremely obese women in order to study true fractional Ca absorption (TFCA) before and 6 months after RYGB surgery, using a dual stable isotope method ((42)Ca and (43)Ca) and test load of Ca (200 mg).
                    • HumanAbsorption of zinc and retention of calcium: dose-dependent inhibition by phytate.
                      J Trace Elem Med Biol, 2006 · Design: stable-isotope · abstract only (PubMed) · closed/paywalled
                      PMID 16632176DOI 10.1016/j.jtemb.2006.01.003
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:The rolls were labelled extrinsically with radioisotopes, 65Zn and 47Ca, and whole-body retention of both minerals was measured.
                      • Key findings · abstract:The zinc absorption in meals to which either 0, 25, 50, 75, 100, 140, 175 or 250 mg of phytate-P (0, 134, 269, 403, 538, 753, 941 or 1344 micromol phytate) had been added was 22%, 16%, 14%, 11%, 7%, 7%, 7% and 6%, respectively (mean values).
                      • Key findings · abstract:The addition of 50 mg phytate-P or more significantly decreased zinc absorption (p=0.01) as compared to absorption from the test meals with no added phytate.
                      • Key findings · abstract:The calcium retention at day 7 in the same meals was 31%, 28%, 27[excerpt truncated in our database — see source]
                      • Food effect · abstract:Totally 105 meals were served, 36 meals in which no phytate was added and 9-10 meals on each level of phytate.
                      • Food effect · abstract:The zinc absorption in meals to which either 0, 25, 50, 75, 100, 140, 175 or 250 mg of phytate-P (0, 134, 269, 403, 538, 753, 941 or 1344 micromol phytate) had been added was 22%, 16%, 14%, 11%, 7%, 7%, 7% and 6%, respectively (mean values).
                      • Food effect · abstract:The addition of 50 mg phytate-P or more significantly decreased zinc absorption (p=0.01) as compared to absorption from the test meals with no added phytate.
                      • Food effect · abstract:The calcium retention at day 7 in the same meals was 31%, 28%, 27%, 26%, 22%, 19%,
                    • HumanRelative bioavailability of calcium from calcium formate, calcium citrate, and calcium carbonate.
                      J Pharmacol Exp Ther, 2005 · Design: crossover · abstract only (PubMed) · open access (green)
                      PMID 15734899DOI 10.1124/jpet.104.081893
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:After calcium carbonate, the maximum rise in serum calcium ( approximately 4%) and the fall in serum intact parathyroid hormone 1-84 (iPTH) (approximately 20-40%) did not differ significantly from placebo.
                      • Key findings · abstract:After calcium citrate, the changes were modestly but significantly (p < 0.05) greater, but only at 135 to 270 min after ingestion.
                      • Key findings · abstract:In contrast, within 60 min after calcium formate serum calcium rose by approximately 15% and serum iPTH fell by 70%.
                      • Key findings · abstract:The mean increment in area under the plasma concentration-time curve (0-270 min) for serum calcium after calcium formate (378 mg . min/dl) w[excerpt truncated in our database — see source]
                      • AUC · abstract:The mean increment in area under the plasma concentration-time curve (0-270 min) for serum calcium after calcium formate (378 mg . min/dl) was double that for calcium citrate (178 mg . min/dl; p < 0.01), whereas the latter was only modestly greater than either placebo (107; p < 0.05) or calcium carbonate (91; p < 0.05).
                      • Food effect · abstract:In a four-way crossover study, either a placebo or 1200 mg of calcium as calcium carbonate, calcium citrate, or calcium formate were administered orally to 14 healthy adult female volunteers who had fasted overnight.
                    • HumanCalcium bioavailability of calcium carbonate fortified soymilk is equivalent to cow's milk in young women.
                      J Nutr, 2005 · Design: crossover; stable-isotope · n: 20 volunteers · abstract only (PubMed) · open access (bronze)
                      PMID 16177199DOI 10.1093/jn/135.10.2379
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:Fractional Ca absorption was determined from the ratios of 43Ca:42Ca and 44Ca:42Ca by inductively coupled plasma (ICP)-MS in the 24-h urine samples.
                      • Key findings · abstract:Fractional Ca absorption in CCSM (0.211 +/- 0.057) did not differ from that of cow's milk (0.217 +/- 0.040), but both were higher (P < 0.05) than that of TCPSM (0.181 +/- 0.039).
                    • HumanCalcium fortification systems differ in bioavailability.
                      J Am Diet Assoc, 2005 · Design: randomized; crossover · abstract only (PubMed) · closed/paywalled
                      PMID 15883561DOI 10.1016/j.jada.2005.02.012
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:The main outcome measure was the area under the curve (AUC) for the increase in serum calcium from 0 to 9 hours after ingesting the test calcium source.
                      • Key findings · abstract:AUC 9 was 48% greater for calcium citrate malate than for tricalcium phosphate/calcium lactate ( P < .001); absorbed calcium calculated from AUC 9 values (mean+/-standard error of the mean) was 148+/-9.0 mg and 100+/-8.9 mg for calcium citrate malate and tricalcium phosphate/calcium lactate, respectively.
                      • AUC · abstract:The main outcome measure was the area under the curve (AUC) for the increase in serum calcium from 0 to 9 hours after ingesting the test calcium source.
                      • AUC · abstract:AUC 9 was 48% greater for calcium citrate malate than for tricalcium phosphate/calcium lactate ( P < .001); absorbed calcium calculated from AUC 9 values (mean+/-standard error of the mean) was 148+/-9.0 mg and 100+/-8.9 mg for calcium citrate malate and tricalcium phosphate/calcium lactate, respectively.
                      • Fractional absorption · abstract:AUC 9 was 48% greater for calcium citrate malate than for tricalcium phosphate/calcium lactate ( P < .001); absorbed calcium calculated from AUC 9 values (mean+/-standard error of the mean) was 148+/-9.0 mg and 100+/-8.9 mg for calcium citrate malate and tricalcium phosphate/calcium lactate, respectively.
                      • Food effect · abstract:Two commercially marketed calcium-fortified orange juices, ingested in an amount providing 500 mg calcium, were taken at breakfast after an overnight fast.
                    • HumanAbsorption of calcium from tortilla meals prepared from low-phytate maize.
                      Am J Clin Nutr, 2005 · Design: stable-isotope · abstract only (PubMed) · open access (PMC)
                      PMID 16002804DOI 10.1093/ajcn.82.1.84PMC1592687 (free full text)
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:Isotope ratios of (42)Ca to (43)Ca and of (44)Ca to (43)Ca were measured by inductively coupled plasma mass spectrometry in urine collected as an 8-h pool from the period 16-24 h after intravenous tracer administration and prepared by the oxalate precipitation method.
                      • Key findings · abstract:RESULTS: Mean fractional absorption of calcium from tortillas prepared from the low-phytate maize (0.50 +/- 0.03) was significantly (P = 0.003) greater than that from tortillas prepared from the control maize (0.35 +/- 0.07).
                      • Fractional absorption · abstract:RESULTS: Mean fractional absorption of calcium from tortillas prepared from the low-phytate maize (0.50 +/- 0.03) was significantly (P = 0.003) greater than that from tortillas prepared from the control maize (0.35 +/- 0.07).
                      • Food effect · abstract:DESIGN: At 1-mo intervals, 5 healthy adult women were fed 2 test meals of approximately 140 g tortillas in lieu of breakfast.
                      • Food effect · abstract:Beginning midway through the test meal, (44)Ca (0.3 mg/kg body wt) was administered in water as an extrinsic label;
                      • Food effect · abstract:(42)Ca (0.06 mg/kg body wt) was administered intravenously immediately after the test meal.
                    • HumanIn vitro determination of calcium bioavailability of milk, dairy products and infant formulas.
                      Int J Food Sci Nutr, 2005 · Design: not stated · abstract only (PubMed) · closed/paywalled
                      PMID 16019311DOI 10.1080/09637480500081423
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:Moreover, it was found that calcium, dry matter, fat content and acidity did not affect the calcium bioavailability (P < 0.05).
                      • Key findings · abstract:According to the results of statistical analysis that was applied to all product groups, it was found that the yogurt group was different from the other products and that the acidity affected calcium bioavailability (P < 0.05).
                    • HumanCalcium from milk or calcium-fortified foods does not inhibit nonheme-iron absorption from a whole diet consumed over a 4-d period.
                      Am J Clin Nutr, 2004 · Design: randomized; crossover · n: 14 women · abstract only (PubMed) · open access (bronze)
                      PMID 15277162DOI 10.1093/ajcn/80.2.404
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:OBJECTIVE: We investigated the effect of 3 sources of calcium served with the 3 main meals on nonheme-iron absorption from a 4-d diet.
                      • Key findings · abstract:DESIGN: (59)Fe absorption was estimated from whole-body retention measurements in 14 women aged 21-34 y, each of whom consumed four 4-d diets in a randomized crossover design.
                      • Key findings · abstract:RESULTS: No significant differences in nonheme-iron absorption were found between the BD and the BD supplemented with milk, calcium lactate, or the milk mineral isolate [7.4% (95% CI: 5.3%, 10.5%), 5.2% (3.5%, 7.9%), 6.7% (5.0%, 8.9%), and 5.1% (3.2%, 7.9%), respectively;[excerpt truncated in our database — see source]
                      • Key findings · abstract:CONCLUSION[excerpt truncated in our database — see source]
                      • Food effect · abstract:OBJECTIVE: We investigated the effect of 3 sources of calcium served with the 3 main meals on nonheme-iron absorption from a 4-d diet.
                      • Food effect · abstract:The diets differed in the source of calcium as follows: a basic diet (BD) with a low content of calcium (224 mg Ca/d), a BD with a glass of milk served at each meal (826 mg Ca/d), a BD with calcium lactate (802 mg Ca/d), and a BD with a milk mineral isolate containing calcium (801 mg Ca/d).
                      • Food effect · abstract:The 2 latter calcium sources were added to selected foods of the BD (rye bread, white bread, chocolate cake, and orange juice), and these foods were consumed with the 3
                    • HumanEffect of age on calcium absorption in postmenopausal women.
                      Am J Clin Nutr, 2004 · Design: not stated · n: 25 women · abstract only (PubMed) · open access (bronze)
                      PMID 15447911DOI 10.1093/ajcn/80.4.998
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:DESIGN: We measured radiocalcium absorption (alpha) in 262 healthy postmenopausal women aged 40-87 y.
                      • Key findings · abstract:RESULTS: Radiocalcium absorption decreased with age (P = 0.018); it was 28% lower in the 25 women aged >75 y than in the rest (P < 0.001).
                      • Key findings · abstract:It was significantly related to serum 1,25-dihydroxyvitamin D [1,25(OH)(2)D] in the whole set and in both the younger and older subsets, but it was not related to either 25-dihydroxyvitamin D [25(OH)D] or PTH or to any other measured variable.
                      • Key findings · abstract:No decrease in 1,25(OH)(2)D was seen with age to account for the decrease in calcium absorption, so radiocalc[excerpt truncated in our database — see source]
                    • HumanEffects of sevelamer hydrochloride and calcium acetate on the oral bioavailability of ciprofloxacin.
                      Am J Kidney Dis, 2003 · Design: randomized; crossover · abstract only (PubMed) · not checked (off-topic)
                      PMID 14655198DOI 10.1053/j.ajkd.2003.08.027
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:The authors conducted a 3-way, randomized, crossover study to determine the effects of sevelamer hydrochloride and calcium acetate on the relative oral bioavailability of ciprofloxacin.
                      • Key findings · abstract:Pharmacokinetic data were analyzed using noncompartmental methods, and maximum serum concentration (Cmax) and area under the serum concentration time curve from 0 to infinity (AUC(0- infinity )) were tested for bioequivalence after log transformation of the data.
                      • Key findings · abstract:The relative oral bioavailability of ciprofloxacin was calculated as AUC(0- infinity ), Arm B or Arm C/AUC(0- infinity ), Arm A.
                      • Key findings · abstract:RESULTS: The Cm[excerpt truncated in our database — see source]
                      • Cmax · abstract:Pharmacokinetic data were analyzed using noncompartmental methods, and maximum serum concentration (Cmax) and area under the serum concentration time curve from 0 to infinity (AUC(0- infinity )) were tested for bioequivalence after log transformation of the data.
                      • Cmax · abstract:RESULTS: The Cmax and AUC(0- infinity ) of ciprofloxacin were significantly decreased when administered concomitantly with sevelamer hydrochloride or calcium acetate (P < 0.05), and bioequivalence was not achieved for either parameter.
                      • AUC · abstract:Pharmacokinetic data were analyzed using noncompartmental methods, and maximum serum concentration (Cmax) and area under the serum concentration time curve from 0 to infinity (AUC(0- infinity )) were tested for bioequivalence after log transformation of the data.
                      • AUC · abstract:The relative oral bioavailability of ciprofloxacin was calculated as AUC(0- infinity ), Arm B or Arm C/AUC(0- infinity ), Arm A.
                      • AUC · abstract:RESULTS: The Cmax and AUC(0- infinity ) of ciprofloxacin were significantly decreased when administered concomitantly with sevelamer hydrochloride or calcium acetate (P < 0.05), and bioequivalence was no
                    • HumanCalcium absorption varies within the reference range for serum 25-hydroxyvitamin D.
                      J Am Coll Nutr, 2003 · Design: randomized · abstract only (PubMed) · closed/paywalled
                      PMID 12672710DOI 10.1080/07315724.2003.10719287
                      Verification: abstract-only auto-extract; unverified
                      • Key findings · abstract:In the first, in which participants were pretreated with 25-hydroxyvitamin D (25OHD), mean serum 25OHD concentration was 86.5 nmol/L; and in the other, with no pretreatment, mean serum concentration was 50.2 nmol/L.
                      • Key findings · abstract:METHODS: Relative calcium absorption at the two 25OHD concentrations was estimated from the area under the curve (AUC) for the load-induced increment in serum total calcium.
                      • Key findings · abstract:RESULTS: AUC(9) (+/- SEM), was 3.63 mg hr/dL +/- 0.234 in participants pretreated with 25OHD and 2.20 +/- 0.240 in those not pretreated (P < 0.001).
                      • Key findings · abstract:In brief, absorption was 65% higher at serum 25OHD leve[excerpt truncated in our database — see source]
                      • AUC · abstract:METHODS: Relative calcium absorption at the two 25OHD concentrations was estimated from the area under the curve (AUC) for the load-induced increment in serum total calcium.
                      • AUC · abstract:RESULTS: AUC(9) (+/- SEM), was 3.63 mg hr/dL +/- 0.234 in participants pretreated with 25OHD and 2.20 +/- 0.240 in those not pretreated (P < 0.001).
                      • Food effect · abstract:Participants received 500 mg oral calcium loads as a part of a standard low calcium breakfast.
                      • Food effect · abstract:Blood was obtained fasting and at frequent intervals for 10 to 12 hours thereafter.
                    • HumanMetabolism of the calcium and bioavailability of the salts of most frequent use.
                      Boll Chim Farm, 2003 · Design: not stated · abstract only (PubMed) · unknown
                      PMID 12680036
                      Verification: abstract-only auto-extract; unverified
                      • HumanPhase I and pharmacokinetic study of a micronized formulation of carboxyamidotriazole, a calcium signal transduction inhibitor: toxicity, bioavailability and the effect of food.
                        Clin Cancer Res, 2002 · Design: clinical trial · abstract only (PubMed) · unknown
                        PMID 11801543
                        Verification: abstract-only auto-extract; unverified
                        • HumanRelative bioavailability of calcium-rich dietary sources in the elderly.
                          Am J Clin Nutr, 2002 · Design: crossover · n: 9 women · abstract only (PubMed) · open access (bronze)
                          PMID 12450902DOI 10.1093/ajcn/76.6.1345
                          Verification: abstract-only auto-extract; unverified
                          • Key findings · abstract:OBJECTIVE: We determined the bioavailability of calcium from 3 different sources: orange juice fortified with calcium-citrate malate, skim milk, and a calcium carbonate supplement.
                          • Key findings · abstract:This finding suggests that the calcium bioavailability from the 3 sources was equivalent.
                          • Key findings · abstract:During the 1-wk high-calcium diet periods, fasting serum calcium increased by 3% (P < 0.0001), serum 1,25-dihydroxyvitamin D decreased by 20% (P < 0.0001), and a biomarker of bone resorption (serum N-telopeptide collagen cross-links) decreased by 14% (P < 0.02) compared with the low-calcium diet period.
                          • Key findings · abstract:CONCLUSIONS: In el[excerpt truncated in our database — see source]
                          • Food effect · abstract:The acute biochemical response to calcium from each of the 3 sources was assessed during a 4-h period after the initial breakfast meal of the high-calcium diet.
                          • Food effect · abstract:During the 1-wk high-calcium diet periods, fasting serum calcium increased by 3% (P < 0.0001), serum 1,25-dihydroxyvitamin D decreased by 20% (P < 0.0001), and a biomarker of bone resorption (serum N-telopeptide collagen cross-links) decreased by 14% (P < 0.02) compared with the low-calcium diet period.
                          • Food effect · abstract:CONCLUSIONS: In elderly subjects, the calcium bioavailability of the 3 high-calcium dietary sources tested was equivalent, during
                        • HumanCalcium absorption from three salts and CaSO(4)-fortified bread in premenopausal women.
                          J Agric Food Chem, 2002 · Design: crossover; stable-isotope · abstract only (PubMed) · closed/paywalled
                          PMID 12059174DOI 10.1021/jf020065g
                          Verification: abstract-only auto-extract; unverified
                          • Key findings · abstract:In study I, calcium fractional absorption levels from the three salts labeled with a stable isotope, 44Ca, were not significantly different (0.039-0.47) as determined by the fecal recovery method.
                          • Key findings · abstract:In a second study, absorption of 45Ca from CaSO(4)-fortified labeled bread or labeled milk was measured in serum exactly 5 h postingestion.
                          • Key findings · abstract:Fractional calcium absorption was slightly but significantly greater from fortified bread than from milk (mean within subject difference = 0.0675 +/- 0.016).
                          • Fractional absorption · abstract:In study I, calcium fractional absorption levels from the three salts labeled with a stable isotope, 44Ca, were not significantly different (0.039-0.47) as determined by the fecal recovery method.
                        • HumanInitial uptake and absorption of nonheme iron and absorption of heme iron in humans are unaffected by the addition of calcium as cheese to a meal with high iron bioavailability.
                          Am J Clin Nutr, 2002 · Design: clinical trial · n: n = 17 · abstract only (PubMed) · open access (bronze)
                          PMID 12145016DOI 10.1093/ajcn/76.2.419
                          Verification: abstract-only auto-extract; unverified
                          • Key findings · abstract:DESIGN: Whole-gut lavage and whole-body scintillation counting methods were applied to determine the 8-h uptake of nonheme iron and the 2-wk retention (absorption) of heme and nonheme iron in healthy adults (n = 17) after the consumption of meals of radiolabeled food.
                          • Key findings · abstract:RESULTS: The initial uptake and absorption of nonheme iron were 11% and 7%, respectively, and the absorption of heme iron was 15%.
                          • Key findings · abstract:Adding calcium (127 mg in cheese) to the meal did not affect absorption.
                          • Food effect · abstract:DESIGN: Whole-gut lavage and whole-body scintillation counting methods were applied to determine the 8-h uptake of nonheme iron and the 2-wk retention (absorption) of heme and nonheme iron in healthy adults (n = 17) after the consumption of meals of radiolabeled food.
                          • Food effect · abstract:Adding calcium (127 mg in cheese) to the meal did not affect absorption.
                        • HumanInfluence of dietary factors on calcium bioavailability: a brief review.
                          Biol Trace Elem Res, 2002 · Design: not stated · abstract only (PubMed) · closed/paywalled
                          PMID 12413050DOI 10.1385/BTER:89:1:43
                          Verification: abstract-only auto-extract; unverified
                          • HumanEffect of estrogen treatment and vitamin D status on differing bioavailabilities of calcium carbonate and calcium citrate.
                            J Clin Pharmacol, 2002 · Design: not stated · abstract only (PubMed) · closed/paywalled
                            PMID 12412824DOI 10.1177/009127002762491343
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Using data derived from a recent trial in 25 postmenopausal women, the authors found that deltaAUC of serum calcium after subtraction of placebo was significantly higher after calcium citrate (median, 0.85; 25th to 75th percentile, 0.70 to 3.15) than after calcium carbonate (0.25; -0.58 to 1.00) in non-estrogen-treated patients.
                            • Key findings · abstract:Bioavailability was also significantly higher with the citrate salt for the subgroups with lower serum 25-hydroxyvitamin D and higher serum 1,25-dihydroxyvitamin D concentrations.
                          • HumanNon-digestible oligosaccharides and calcium absorption in girls with adequate calcium intakes.
                            Br J Nutr, 2002 · Design: randomized; crossover; stable-isotope · abstract only (PubMed) · closed/paywalled
                            PMID 12088517DOI 10.1079/BJNBJN/2002536
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:The objective of this study was to assess the effect of 8 g/d of oligofructose or a mixture of inulin and oligofructose on calcium absorption in girls at or near menarche.
                            • Key findings · abstract:At the end of each 3-week adaptation period, calcium absorption was measured, using a dual stable isotope technique, from the cumulative fractional excretion of an oral and an intravenous tracer over 48 hours.
                          • HumanHigh bioavailability of calcium in fortified Horlicks.
                            Eur J Clin Nutr, 2001 · Design: randomized; crossover; stable-isotope · abstract only (PubMed) · closed/paywalled
                            PMID 11528493DOI 10.1038/sj.ejcn.1601224
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:RESULTS: Mean true fractional calcium absorption was 38.8% (s.d.+/-14.5) from Horlicks and 21.2% (s.d.+/-4.6) from milk.
                            • Key findings · abstract:Significantly more calcium was absorbed from a serving of Horlicks than from the same quantity of calcium present in 420 g semi-skimmed milk (P<0.001).
                            • Fractional absorption · abstract:Significantly more calcium was absorbed from a serving of Horlicks than from the same quantity of calcium present in 420 g semi-skimmed milk (P<0.001).
                          • HumanAbsorbability and cost effectiveness in calcium supplementation.
                            J Am Coll Nutr, 2001 · Design: randomized; crossover · abstract only (PubMed) · closed/paywalled
                            PMID 11444420DOI 10.1080/07315724.2001.10719038
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:SUBJECTS: 24 postmenopausal women METHODS: Pharmacokinetic analysis of the increment in serum total and ionized calcium and the decrement in serum iPTH induced by an oral calcium load, based upon multiple blood samples over a 24-hour period; measurement of the rise in urine calcium excretion.
                            • Key findings · abstract:RESULTS: All three calcium sources (marketed calcium carbonate, encapsulated calcium carbonate and marketed calcium citrate) produced identical 24-hour time courses for the increment in total serum calcium.
                          • HumanEffect of reproduction on the bioavailability of calcium, zinc and selenium.
                            J Nutr, 2001 · Design: stable-isotope · abstract only (PubMed) · open access (bronze)
                            PMID 11285354DOI 10.1093/jn/131.4.1355S
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Calcium absorption increased approximately 2-fold during pregnancy but dropped to values for nonpregnant women during lactation.
                            • Key findings · abstract:In women chronically consuming a low calcium diet, fractional calcium absorption increased to >80% during reproduction.
                            • Key findings · abstract:Selenium absorption was high, approximately 80% of intake, in both pregnant and nonpregnant women.
                            • Relative bioavailability · abstract:Calcium absorption increased approximately 2-fold during pregnancy but dropped to values for nonpregnant women during lactation.
                          • HumanCalcium, iron, and zinc uptake from digests of infant formulas by Caco-2 cells.
                            J Agric Food Chem, 2001 · Design: not stated · abstract only (PubMed) · closed/paywalled
                            PMID 11453795DOI 10.1021/jf010106t
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Our aim was to estimate the bioavailability of calcium, iron, and zinc from infant formulas using a model that includes in vitro digestion and a Caco-2 cell culture to estimate the uptake.
                          • HumanAcute biochemical variations induced by calcium citrate and calcium carbonate in Type 2 diabetic patients: impaired calcium absorption in Type 2 diabetic patients with prolonged gastric emptying time.
                            J Diabetes Complications, 2001 · Design: not stated · abstract only (PubMed) · closed/paywalled
                            PMID 11274906DOI 10.1016/s1056-8727(00)00128-8
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Serum free calcium, intact parathyroid hormone (i-PTH), and amount of urinary excretion of calcium (uCal/uCr) were evaluated after a single dose of 1200 mg of elemental calcium in each preparation.
                            • Key findings · abstract:After administration of calcium citrate, the uCal/uCr of 2-to-4-h collection was significantly higher than that of the basal and 0-to-2-h collections: 0.25+/-0.04 vs. 0.19+/-0.03, P=.025; and 0.25+/-0.04 vs. 0.19+/-0.02, P=.014, respectively.
                          • HumanCarbonated beverages and urinary calcium excretion.
                            Am J Clin Nutr, 2001 · Design: randomized · abstract only (PubMed) · open access (bronze)
                            PMID 11522558DOI 10.1093/ajcn/74.3.343
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:RESULTS: Relative to water, urinary calcium rose significantly only with the milks and the 2 caffeine-containing beverages.
                            • Food effect · abstract:Beverages were consumed with a light breakfast after an overnight fast; no other foods were ingested until urine collection was complete. pH, titratable and total acidity, sodium, creatinine, and calcium were measured in 2-h (morning) fasting and 5-h postbeverage urine specimens.
                          • HumanPharmacokinetic and pharmacodynamic comparison of two calcium supplements in postmenopausal women.
                            J Clin Pharmacol, 2000 · Design: randomized; crossover · abstract only (PubMed) · unknown
                            PMID 11075309
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:This randomized crossover study compared the single-dose bioavailability and effects on parathyroid function of two commercially formulated calcium supplements containing 500 mg of elemental calcium.
                            • Key findings · abstract:Compared with calcium carbonate, calcium citrate provided a 46% greater peak-basal variation and 94% higher change in area under the curve for serum calcium and a 41% greater increment in urinary calcium.
                            • AUC · abstract:Compared with calcium carbonate, calcium citrate provided a 46% greater peak-basal variation and 94% higher change in area under the curve for serum calcium and a 41% greater increment in urinary calcium.
                            • Food effect · abstract:Twenty-five postmenopausal women underwent three phases of study wherein they each took a single dose of calcium citrate with a standard breakfast (as Citracal 250 mg + D), calcium carbonate (as Os-Cal 500 mg + D), or placebo at 8 a.m.
                          • HumanThe effect of calcium on iron absorption.
                            Nutr Res Rev, 2000 · Design: not stated · abstract (PubMed); full-text PDF saved · open access (bronze)
                            PMID 19087437DOI 10.1079/095442200108729043PDF
                            Verification: full-text auto-extracted verbatim snippets with location; needs human check
                            • Fractional absorption · full text, p.6:gether with a hamburger meal. Absorption was reduced by 24% when 300 mg Ca was taken with 37 mg Fe as FeSO4 (P ˆ 0043). With 600 mg Ca and 18 mg Fe, absorption was 44% lower in subjects with reduced Fe stores (P < 0001), but not sig- https://doi.org/10.1079/095442200108729043 Published online by Cambridge University Press
                            • Fractional absorption · full text, p.11:er meals that provided most of the dietary Fe, and during the other period the dairy products were provided more evenly throughout the day's diet. Fe absorption was 32% higher when dairy products were eliminated from the main Fe-containing meals. In summary, all but one of the multiple-meal studies indicate that Ca is likely to have a far smaller in¯uence on Fe absorption than would be predicted f
                            • Food effect · full text, p.4:eanling rats given large amounts of Ca in their diets (Fuhr & Steenbock, 1943). Young female mice and their litters became anaemic when the dams were fed high doses of CaCO3 (Greig, 1952). Although the majority of experiments carried out in experimental animals have demonstrated an inhibitory effect of Ca, the ®nding has not been universal. Wauben & Atkinson (1999) recently reported that Ca did no
                            • Food effect · full text, p.5:le information has been obtained by using radioisotopes or stable isotopes to tag the common Fe pools in food or an Fe supplement given either in the fasting state or with food. Several Ca salts that are recommended as supplements have been evaluated (Tables 1 and 2). Monsen & Cook (1976) demonstrated that the addition of 178 mg Ca as CaCl2 to a meal composed of semi-puri®ed ingredients and contai
                            • Food effect · full text, p.6:unt for the observed dif- ference in absorption. Dawson-Hughes et al. (1986) reported that the ingestion of a CaCO3 supplement con- taining 500 mg Ca with a breakfast meal reduced the intrinsic food Fe absorption to about 43% of the control value (P ˆ 0002). Cook et al. (1991b) con®rmed and extended their ®ndings. First, they measured the effect of a 600 mg CaCO3 supplement on intrinsic food Fe a
                            • Form comparison · full text, p.4:the corresponding percentages for men and children aged 2 ±6 years are 14 and 75 respectively. The median dose (mg/d) is also highest in women, 248 compared with 160 and 88 for men and children respectively. Effect of calcium salts and dairy products on iron absorption The effect of several Ca salts and dairy products on Fe absorption has been tested in both experimental animals and human volunte
                            • Form comparison · full text, p.14:vehicles for forti®cation with Fe unless steps are taken to improve bioavailability. References Ames SK, Gorham BM & Abrams SA (1999) Effects of high compared with low calcium intake on calcium absorption and incorporation of iron by red blood cells in small children. American Journal of Clinical Nutrition 70, 44 ± 48. https://doi.org/10.1079/095442200108729043 Published online by Cambridge Univer
                          • HumanTransgalactooligosaccharides stimulate calcium absorption in postmenopausal women.
                            J Nutr, 2000 · Design: randomized; crossover; double-blind; stable-isotope · n: 12 subjects · abstract only (PubMed) · open access (bronze)
                            PMID 11110850DOI 10.1093/jn/130.12.2938
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Before and during the 36 h after isotope administration, urine was collected and the ratios of isotopes present were measured by inductively coupled plasma mass spectrometry (ICP-MS).
                            • Key findings · abstract:TOS increased true calcium absorption 16%, from (mean +/- SD) 20.6 +/- 7.0% during the reference treatment to 23.9 +/- 6.9% during the TOS treatment (P: = 0.04, one-sided).
                            • Food effect · abstract:During the treatment periods, 12 subjects drank 200 mL yogurt drink twice (at breakfast and lunch) containing either TOS (20 g/d) or the reference substance, sucrose.
                          • HumanRelationship of intestinal calcium absorption to 1,25-dihydroxyvitamin D [1,25(OH)2D] levels in young versus elderly women: evidence for age-related intestinal resistance to 1,25(OH)2D action.
                            J Clin Endocrinol Metab, 2000 · Design: stable-isotope · n: n = 20 · abstract only (PubMed) · open access (bronze)
                            PMID 11095427DOI 10.1210/jcem.85.11.6938
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Intestinal calcium absorption decreases with aging, but it is unclear whether this is attributable to an age-related intestinal resistance to 1,25-dihydroxyvitamin D [1,25(OH)2D] action.
                            • Key findings · abstract:Thus, we assessed the in vivo dose response of active intestinal calcium absorption to a broad range of circulating 1,25(OH)2D levels in elderly [age (mean +/- SD), 72.5+/-3.0 yr] vs. young women (age, 28.7+/-5.3 yr; n = 20 per group), who were stratified into 5 subgroups: group 1 was given a high calcium intake of 75 mmol/day, suppressing 1,25(OH)2D levels; group 2 was given a normal calcium diet of 15-30 m[excerpt truncated in our database — see source]
                            • Food effect · abstract:After 7 days of diet and/or 1,25(OH)2D treatment, fasting fractional calcium absorption (FCA) was assessed by a double-tracer method using stable calcium isotopes.
                          • HumanThe pharmacokinetics of extended-release formulations of calcium antagonists and of amlodipine in subjects with different gastrointestinal transit times.
                            J Clin Pharmacol, 1999 · Design: randomized; crossover · abstract only (PubMed) · closed/paywalled
                            PMID 10516936DOI 10.1177/00912709922011782
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:AUC 1134.4 +/- 512.7 versus 1704.7 +/- 1185.6 hng/ml, p < 0.05 (one-sided).
                            • Key findings · abstract:Peak-to-trough ratios (Cmax/C24 h mean) were 1.8 +/- 0.9 for DIL, 7.6 +/- 3.5 for FEL, and 1.7 +/- 0.2 for AML.
                            • Cmax · abstract:Peak-to-trough ratios (Cmax/C24 h mean) were 1.8 +/- 0.9 for DIL, 7.6 +/- 3.5 for FEL, and 1.7 +/- 0.2 for AML.
                            • AUC · abstract:AUC 1134.4 +/- 512.7 versus 1704.7 +/- 1185.6 hng/ml, p < 0.05 (one-sided).
                          • HumanPharmacokinetics of calcium absorption from two commercial calcium supplements.
                            J Clin Pharmacol, 1999 · Design: clinical trial · abstract only (PubMed) · unknown
                            PMID 10579145
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:This study was conducted to compare pharmacokinetic indices of calcium absorption after a single oral (500 mg calcium) load of Citracal (calcium citrate) and Os-Cal (calcium carbonate).
                            • Key findings · abstract:The change in area under the curve (delta AUC) in serum calcium from preload was 2.5-fold greater for Citracal than Os-Cal, and the peak-basal variation in serum calcium was 76% higher for Citracal than Os-Cal.
                            • Key findings · abstract:The increment in serum calcium from preload after Citracal administration was significantly higher than that obtained after placebo load during most time periods and significantly higher than that of[excerpt truncated in our database — see source]
                            • AUC · abstract:The change in area under the curve (delta AUC) in serum calcium from preload was 2.5-fold greater for Citracal than Os-Cal, and the peak-basal variation in serum calcium was 76% higher for Citracal than Os-Cal.
                            • AUC · abstract:In contrast, delta AUC and peak basal variation of Os-Cal did not differ significantly from placebo and increment in serum calcium was significantly increased from placebo only at 6 hours.
                            • Relative bioavailability · abstract:The change in area under the curve (delta AUC) in serum calcium from preload was 2.5-fold greater for Citracal than Os-Cal, and the peak-basal variation in serum calcium was 76% higher for Citracal than Os-Cal.
                            • Food effect · abstract:In 18 postmenopausal normal women, venous blood samples were obtained for the measurement of calcium before and hourly for 6 hours after an oral ingestion of Citracal, Os-Cal, or placebo with a breakfast meal.
                          • HumanPopulation pharmacokinetic of nadroparin calcium (Fraxiparine) in children hospitalised for open heart surgery.
                            Eur J Pharm Sci, 1999 · Design: clinical trial · n: 154 children · abstract only (PubMed) · closed/paywalled
                            PMID 10210734DOI 10.1016/s0928-0987(98)00064-5
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:The 432 anti-Xa activities were analysed using NONMEM on the basis of a one-compartment model with three parameters: apparent clearance, apparent volume of distribution and absorption rate.
                          • HumanCalcium bioavailability and parathyroid hormone acute changes after oral intake of dairy and nondairy products in healthy volunteers.
                            Osteoporos Int, 1999 · Design: not stated · abstract only (PubMed) · closed/paywalled
                            PMID 10501794DOI 10.1007/s001980050208
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:This study was designed to compare calcium bioavailability and serum parathyroid hormone acute changes after oral intake of 500 mg of elemental calcium from liquid milk, yogurt, calcium-citrate-enriched powdered milk or a calcium carbonate pill; or after intake of soybean imitation-milk.
                            • Key findings · abstract:Calcium-citrate-enriched powdered milk induced a significant increase in serum ionized calcium (p<0.001) and a significant and continuous decrease in serum iPTH concentration (p<0. 001).
                            • Key findings · abstract:Yogurt and the calcium carbonate pill induced a similar but less significant effect, increasing serum ionized calcium (p[excerpt truncated in our database — see source]
                            • Food effect · abstract:After a 12-h fast, blood samples were drawn both at baseline and 1, 2, 3 and 4 h after an oral intake of the above-mentioned products, which were ingested together with a light neutral breakfast.
                          • HumanLactulose stimulates calcium absorption in postmenopausal women.
                            J Bone Miner Res, 1999 · Design: randomized; crossover; double-blind; stable-isotope · abstract only (PubMed) · open access (green)
                            PMID 10404023DOI 10.1359/jbmr.1999.14.7.1211
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Based on isotope ratios measured in urine collected before and until 36 h after isotope administration, true fractional calcium absorption was calculated.
                            • Key findings · abstract:Calcium absorption during the treatments with the reference substance, 5 g and 10 g of lactulose was (mean +/- SD) 27.7 +/- 7.7, 30.0 +/- 7.6, and 32.2 +/- 7.0, respectively.
                            • Key findings · abstract:A significant difference in calcium absorption was found between the highest dose of lactulose and the reference treatment (p < 0.01).
                            • Key findings · abstract:In conclusion, in postmenopausal women a 9-day consumption of lactulose increases calcium absorption in a dose-response way.
                            • Food effect · abstract:Twelve postmenopausal women drank 100 ml of water containing 5 or 10 g of lactulose or a reference substance at breakfast for 9 days.
                            • Food effect · abstract:On the 8th day of each treatment period, 44Ca dissolved in orange juice was drunk immediately after the solution with the study substance and just before a standard breakfast with 162 mg of carrier calcium.
                          • HumanIntegrated pharmacokinetics and pharmacodynamics of the novel calcium sensitizer levosimendan as assessed by systolic time intervals.
                            Int J Clin Pharmacol Ther, 1998 · Design: not stated · abstract only (PubMed) · unknown
                            PMID 9876999
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Plasma concentrations of levosimendan and its metabolite OR-1855 were analyzed using HPLC.
                            • Key findings · abstract:The bioavailability of CT and CC was 83 and 87%, while that of SR was only 31%.
                            • Key findings · abstract:Only after SR, OR-1855 was detected in appreciable amounts in plasma, the highest value being 2.2 ng x ml(-1) which occurred 24 hours after drug intake.
                            • Key findings · abstract:CONCLUSION: In conclusion, the pharmacokinetic-dynamic behavior of the inotropy index QS2i indicates an equilibration delay of levosimendan, which most probably reflects the time the drug requires to distribute from plasma to its cardiac site of action.
                          • HumanDietary protein affects intestinal calcium absorption.
                            Am J Clin Nutr, 1998 · Design: randomized; stable-isotope · abstract only (PubMed) · open access (bronze)
                            PMID 9771863DOI 10.1093/ajcn/68.4.859
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:OBJECTIVE: We reexamined this mechanism by evaluating the effect of 2 amounts of dietary protein (low: 0.7 g/kg; and high: 2.1 g/kg) on fractional calcium absorption in 7 healthy, young women.
                            • Key findings · abstract:Fractional calcium absorption was measured by dual-stable calcium isotopes on day 5.
                            • Key findings · abstract:Urinary calcium excretion and the glomerular filtration rate were elevated significantly by day 4 of the high-protein compared with the low-protein diet.
                            • Key findings · abstract:Fractional calcium absorption after the low-protein diet was 0.19+/-0.03, which was significantly lower than that after the high-protein diet (0.26+/-0.03, P=0.05[excerpt truncated in our database — see source]
                          • HumanComparative study of the intestinal absorption of three salts of calcium in young and elderly women.
                            J Endocrinol Invest, 1998 · Design: not stated · n: n = 7 · abstract only (PubMed) · closed/paywalled
                            PMID 9624602DOI 10.1007/BF03347313
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:We have compared the digestive absorption of calcium (Ca) citrate in soluble and solid form and calcium gluconolactate-carbonate in 15 young and 20 elderly, healthy women using the oral calcium loading test.
                            • Key findings · abstract:In the first group, the absorption of solid Ca citrate (1000 mg Ca element) was compared to the absorption of Ca gluconolactate-carbonate (1000 mg Ca element) both in young (n = 7) and elderly women (n = 10).
                            • Key findings · abstract:In the second group, the absorption of soluble Ca citrate (1000 mg Ca element) was compared to the absorption of Ca gluconolactate-carbonate (1000 mg Ca element) in young (n = 8)
                          • HumanEffect of dietary calcium on urinary oxalate excretion after oxalate loads.
                            Am J Clin Nutr, 1997 · Design: not stated · abstract only (PubMed) · open access (bronze)
                            PMID 9129476DOI 10.1093/ajcn/65.5.1453
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Mean 24-h oxalate absorption decreased significantly from that at the time of the baseline treatment (18.3%) after both calcium carbonate (8.1%) and CCM (7.2%) treatments.
                            • Key findings · abstract:In R-2, mean 24-h oxalate absorption was significantly lower after 200 (5.9%) and 300 (7.6%) mg Ca than after 100 mg Ca (9.1%) and the OL alone (11.3%).
                            • Key findings · abstract:Concomitant meal ingestion significantly decreased oxalate absorption in the absence of dietary calcium but not in association with the 300-mg Ca treatment.
                            • Food effect · abstract:Concomitant meal ingestion significantly decreased oxalate absorption in the absence of dietary calcium but not in association with the 300-mg Ca treatment.
                          • HumanCalcium retention in relation to calcium intake and postmenarcheal age in adolescent females.
                            Am J Clin Nutr, 1997 · Design: crossover · n: 14 subjects · abstract only (PubMed) · open access (bronze)
                            PMID 9250111DOI 10.1093/ajcn/66.2.327
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Mean maximal calcium retention was 473 mg/d (95% CI: 245, 701 mg Ca/d).
                            • Key findings · abstract:Calcium intake explained 79% and 6%, respectively, of the variation in fecal and urinary calcium excretion.
                            • Key findings · abstract:Intake of 1200 mg Ca/d, the recommended dietary allowance for calcium published in 1989, resulted in a mean calcium retention that was 57% of the maximal value (95% CI: 25%, 89%).
                            • Key findings · abstract:Intake of 1300 mg Ca/d was the smallest intake that allowed some adolescent females to achieve 100% of maximal calcium retention (95% CI: 26%, 100%).
                            • Key findings · abstract:These data support the idea that calcium retention plateaus at a certain calcium i[excerpt truncated in our database — see source]
                          • HumanPostprandial parathyroid hormone response to four calcium-rich foodstuffs.
                            Am J Clin Nutr, 1997 · Design: randomized · abstract only (PubMed) · open access (bronze)
                            PMID 9174467DOI 10.1093/ajcn/65.6.1726
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:The serum ionized calcium concentration increased significantly after ingesting cheese (P = 0.004, contrast analysis) or calcium salt (P = 0.05, contrast analysis) compared with the control session.
                            • Key findings · abstract:Compared with the control session, the serum phosphate concentration increased after the cheese session (P = 0.004, contrast analysis) and after the milk session (P = 0.02, contrast analysis).
                            • Key findings · abstract:Calcium salt (P = 0.007, contrast analysis) and cheese (P = 0.002, contrast analysis) caused a significant decline in serum intact parathyroid hormone compared with the control session.
                            • Key findings · abstract:The urinary calc[excerpt truncated in our database — see source]
                            • Food effect · abstract:Four hundred milligrams calcium from either Emmental cheese, milk, sesame seeds, spinach, or calcium salt (calcium lactate gluconate + calcium carbonate) or no additional calcium (control session) were given to nine female volunteers immediately after a first blood sample (at 0900) in random order with a light standardized meal containing 37 mg Ca.
                          • HumanCalcium bioavailability from bovine milk and dairy products in premenopausal women using intrinsic and extrinsic labeling techniques.
                            J Nutr, 1996 · Design: stable-isotope · abstract only (PubMed) · open access (bronze)
                            PMID 8618137DOI 10.1093/jn/126.5.1406
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Healthy Caucasian women were fed a controlled diet for 4 d during the follicular phase of their menstrual cycle.
                            • Key findings · abstract:Fractional absorption was determined as the difference between the administered isotopic dose and the quantity of 44Ca or 42Ca excreted in feces.
                            • Fractional absorption · abstract:Fractional absorption was determined as the difference between the administered isotopic dose and the quantity of 44Ca or 42Ca excreted in feces.
                            • Food effect · abstract:Healthy Caucasian women were fed a controlled diet for 4 d during the follicular phase of their menstrual cycle.
                            • Food effect · abstract:With breakfast on the third day, participants ingested milk containing 44Ca (intrinsic) and 42CaCl2 (extrinsic) or dairy products containing 44Ca.
                          • HumanIntestinal calcium absorption from different calcium preparations: influence of anion and solubility.
                            Osteoporos Int, 1996 · Design: randomized; stable-isotope · n: 18 healthy volunteers · abstract only (PubMed) · closed/paywalled
                            PMID 8931033DOI 10.1007/BF01623012
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:In the present study, the bioavailability of calcium citrate and calcium lactogluconate/carbonate from a therapeutic dose (= 500 mg Ca2+) was compared in men aged between 45 and 60 years on an intra-individual basis.
                            • Key findings · abstract:Using a double-isotope method, the intestinal absorption from the three preparations was determined in randomized order at intervals of 2-4 weeks.
                            • Key findings · abstract:The intestinal calcium absorption was then determined after 24 h on the basis of the ratio of the two isotopes in the plasma.
                            • Key findings · abstract:There was a significantly higher absorption of 29% from the citrate solution than from the lactogluconat[excerpt truncated in our database — see source]
                          • HumanBioavailability of calcium supplements and the effect of Vitamin D: comparisons between milk, calcium carbonate, and calcium carbonate plus vitamin D.
                            Am J Clin Nutr, 1996 · Design: randomized; crossover · n: 20 healthy women · abstract only (PubMed) · open access (bronze)
                            PMID 8602592DOI 10.1093/ajcn/63.3.354
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Bioavailability of the different calcium-supplement regimens were evaluated by changes in 24-h urinary excretion of calcium, phosphate, and magnesium.
                            • Key findings · abstract:A significant increase in urinary calcium excretion was found during all periods of supplementation compared with the placebo period (P<0.01).
                            • Key findings · abstract:We conclude that the examined calcium carbonate regimen is at least as good a calcium supplement as milk, and that addition of 600 IU vitamin D/d promptly resulted in an increase in urinary calcium excretion after an increase in calcium absorption, even in healthy women.
                          • HumanDifferences in calcium kinetics between adolescent girls and young women.
                            Am J Physiol, 1996 · Design: stable-isotope · n: 11 women · abstract only (PubMed) · closed/paywalled
                            PMID 8760222DOI 10.1152/ajpregu.1996.271.1.R208
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Samples were analyzed for total calcium by atomic absorption spectrophotometry and for enrichment of 42Ca and 44Ca by fast atom bombardment mass spectrometry.
                            • Key findings · abstract:Compared with the women, girls absorbed more calcium from the diet (38 vs. 22% or 494 vs. 283 mg/day), excreted less calcium in urine (100 vs. 203 mg/day), deposited more calcium in bone (1,459 vs. 501 mg/day), and resorbed more calcium from the skeleton (1,177 vs. 542 mg/day), whereas endogenous calcium excretion did not differ between girls and women (112 vs. 121 mg/day).
                            • Key findings · abstract:Girls retained more calcium than women (282 vs. -41 mg/day)
                            • Fractional absorption · abstract:Compared with the women, girls absorbed more calcium from the diet (38 vs. 22% or 494 vs. 283 mg/day), excreted less calcium in urine (100 vs. 203 mg/day), deposited more calcium in bone (1,459 vs. 501 mg/day), and resorbed more calcium from the skeleton (1,177 vs. 542 mg/day), whereas endogenous calcium excretion did not differ between girls and women (112 vs. 121 mg/day).
                          • HumanEffect of gastric acid secretion on intestinal phosphate and calcium absorption in normal subjects.
                            Nephrol Dial Transplant, 1995 · Design: crossover · abstract only (PubMed) · unknown
                            PMID 8538929
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:In eight normal subjects we measured 24-h urinary calcium phosphate excretion and the postprandial blood calcium phosphate profile after a meal containing 1 g of calcium and 2 g of phosphate salts in a crossover placebo-omeprazole study.
                            • Key findings · abstract:RESULTS: Serum gastrin levels were measured as an indicator of achlorhydria and were 13.7 +/- 1 pg/ml after placebo and 30.4 +/- 4.7 after omeprazole (P < 0.003).
                            • Key findings · abstract:Postprandial plasma phosphate profiles were not significantly different between the two studies (+36 +/- 8% after placebo and +24 +/- 8% after omeprazole, NS), while plasma calcium increased by +[excerpt truncated in our database — see source]
                            • Food effect · abstract:In eight normal subjects we measured 24-h urinary calcium phosphate excretion and the postprandial blood calcium phosphate profile after a meal containing 1 g of calcium and 2 g of phosphate salts in a crossover placebo-omeprazole study.
                            • Food effect · abstract:Postprandial plasma phosphate profiles were not significantly different between the two studies (+36 +/- 8% after placebo and +24 +/- 8% after omeprazole, NS), while plasma calcium increased by +6.1 +/- 1% after placebo and decreased by -4.2 +/- 0.7% after omeprazole (P < 0.01).
                          • HumanHypochlorhydria from short-term omeprazole treatment does not inhibit intestinal absorption of calcium, phosphorus, magnesium or zinc from food in humans.
                            J Am Coll Nutr, 1995 · Design: clinical trial · n: n = 5 · abstract only (PubMed) · closed/paywalled
                            PMID 8568113DOI 10.1080/07315724.1995.10718522
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Mineral absorption was measured twice in each subject, once with 120 mL of 0.1 mol/liter hydrochloric acid and a second time with 120 mL of distilled water alone.
                            • Food effect · abstract:Omeprazole treatment of normal volunteers resulted in a significant change in postprandial gastric pH (pH 6.4 +/- 0.3 vs. 3.6 +/- 0.5 in control subjects, p < 0.01) and baseline fasting pH (pH 5.8 +/- 0.5 vs. pH 1.8 +/- 0.3 in controls, p < 0.01) after an overnight fast.
                          • HumanTrue fractional calcium absorption in Chinese children measured with stable isotopes (42Ca and 44Ca).
                            Br J Nutr, 1994 · Design: stable-isotope · abstract (PubMed); full-text PDF saved · open access (bronze)
                            PMID 7827009DOI 10.1079/bjn19940093PDF
                            Verification: full-text auto-extracted verbatim snippets with location; needs human check
                            • Key findings · abstract:TFCA of a lower-Ca-intake group (Ca < or = 500 mg/d, n19) with mean Ca intake 359 mg/d was 63.1 (SD 10.7)% and that of a higher-Ca-intake group (Ca > 500 mg/d, n15) with mean Ca intake 862 mg/d was 54.8 (SD 7.3)%; the difference in TFCA was significant (P = 0.016).
                            • Key findings · abstract:Serum levels of 25-hydroxycholecalciferol of the children were adequate (33.7 (SD 7.7) ng/ml).
                            • Key findings · abstract:If it is assumed that dietary Ca absorption by Chinese children resembles their TFCA from a single meal of chocolate milk, then the recommended dietary allowance (RDA) for Ca for Chinese children would be lower than the US RDA (800 mg/[excerpt truncated in our database — see source]
                            • Food effect · abstract:If it is assumed that dietary Ca absorption by Chinese children resembles their TFCA from a single meal of chocolate milk, then the recommended dietary allowance (RDA) for Ca for Chinese children would be lower than the US RDA (800 mg/d), which is based on an estimated 40% Ca absorption as reported for Caucasian children.
                            • Fractional absorption · full text, p.1:https://doi.org/10.1079/BJN19940093 Published online by Cambridge University Press British Journal of Nutrition (1994), 72, 883-897 883 True fractional calcium absorption in Chinese children measured with stable isotopes (42Caand 'Wa) BY W A R R E N T. K. LEE', S O P H I E S. F. LEUNG', SU SA N J. FA IRWE A T H E R- TAIT', D O R A M. Y. LEUNGl, H E I D I S. Y. TSANG', J O H N EAGLES', T O M FOX2,
                            • Fractional absorption · full text, p.7:a intake at 550 mg/d (1500 mg/d) was excluded from the classification due to inadequate sample size. Table 3. Mean dietary intake, body size and true fractional calcium absorption (TFCA) of 7- year-old Hongkong and Jiangmen children classijied according to calcium intake into groups A (Ca d 500 m g / d ) and B (Ca > 500 mg/d)* (Mean values and standard deviations) Study group.. . A (n 19) B (n 15)
                            • Fractional absorption · full text, p.9://doi.org/10.1079/BJN19940093 Published online by Cambridge University Press C A ABSORPTION IN CHINESE CHILDREN 891 Table 5. Comparisons of mean true fractional calcium absorption (TFCA) of 7-year-old Hongkong and Jiangmen children classified according to location and C a intake into groups C (Hongkong, C a < 500 m g l d ) , D (Jiangman, C a d 500 m g / d ) and E (Hongkong, Ca>500 m g / d ) (Mean
                            • Food effect · full text, p.3:y in choosing the food items in the questionnaire either per d, per week, or per month. Nutrient intake was estimated using a computerized food table with food items compiled from appropriate sources (Tung et al. 1961; Department of Health, Education & Welfare, 1972; Church & Church, 1975; Paul & Southgate, 1978; Institute of Health, 1980; Watt & Merrill, 1983), food manufacturers and food chemist
                            • Food effect · full text, p.12:on between serum 25-OHD concentration and baseline TFCA ( r -0.29, P = 0.21, n 20). Almost all the Jiangmen children in the current study were breast-fed up to 10 months of age. Only one girl was formula-fed from birth to 15 months, and five children were supplemented with formula milk up to about 12 months of age because the mothers could not produce adequate amounts of breast milk. After 1 year
                            • Food effect · full text, p.13:8) and Smith et al. (1987). In addition, oral 44Cawas administered in chocolate milk as a tracer carrier and the test meal was given to subjects in a fasted state. In contrast, Miller et al. (1988) and Smith et al. (1987) labelled Ca salts with 44Ca(total dose 250mg Ca) and the oral tracer was taken simultaneously with a standard breakfast. Thus, it is inconclusive whether the discrepancy in TFCA
                            • Form comparison · full text, p.13:4 (SD 8-4)%, and the mean dietary Ca intake of the ten subjects was 940 (SD 470) mg/d. The higher percentages of TFCA found in the present study when compared with those of Abrams et al. (1993) may be due to adaptive or ethnic differences in the efficiency of Ca absorption, or slight variations in the study protocols. Miller et al. (1988) and Smith et al. (1987) used a double- isotope technique to
                          • HumanComparison of serum calcium levels between junior high school children with high-normal and low-normal blood pressure. The child and adolescent blood pressure program.
                            Am J Hypertens, 1994 · Design: randomized · n: 243 children · abstract only (PubMed) · closed/paywalled
                            PMID 7702797DOI 10.1093/ajh/7.12.1045
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Calcium measurements were based on the principle that serum calcium is found in three forms: 1) an ionized fraction; 2) a fraction complexed with organic anions such as citrate, phosphate, and lactate; and 3) a protein-bound fraction.
                            • Key findings · abstract:Dietary calcium intake was determined from food diaries, and urinary electrolytes were determined in 24-h urine collections.
                            • Key findings · abstract:This report of the relation between calcium and blood pressure represents the first study in children or adolescents to include serum, dietary, and urine data.(ABSTRACT TRUNCATED AT 250 WORDS)
                          • HumanPharmacokinetics and pharmacodynamics of simendan, a novel calcium sensitizer, in healthy volunteers.
                            Clin Pharmacol Ther, 1994 · Design: clinical trial · abstract only (PubMed) · closed/paywalled
                            PMID 7955820DOI 10.1038/clpt.1994.177
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:RESULTS: The area under the plasma concentration time-curve increased linearly and correlated with dose (p < 0.001).
                            • Key findings · abstract:The increase in maximal ejection fraction (EF) correlated significantly with the plasma concentrations of simendan (p < 0.01; r2 = 0.33).
                            • Key findings · abstract:However, the correlation coefficient was higher between estimated concentrations of simendan in peripheral compartment and ejection fraction; r2 was 0.79 (p < 0.01) and 0.94 (p < 0.001) after 2 and 5 mg doses, respectively.
                            • AUC · abstract:RESULTS: The area under the plasma concentration time-curve increased linearly and correlated with dose (p < 0.001).
                          • HumanEffect of added citrate or malate on calcium absorption from calcium-fortified orange juice.
                            J Am Coll Nutr, 1994 · Design: randomized · abstract only (PubMed) · closed/paywalled
                            PMID 7706589DOI 10.1080/07315724.1994.10718450
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:OBJECTIVE: Calcium absorption was determined from calcium-fortified diluted orange juice, which contained additional citrate or malate, in 16 normal subjects.
                            • Key findings · abstract:For each subject, fractional (intestinal) calcium absorption was measured by taking the ratio of fractional forearm radioactivity following an oral administration of OJ+C or OJ+M (labeled with 47Ca) and the fractional forearm radioactivity obtained after intravenous administration of trace 47Ca chloride on a separate occasion.
                            • Key findings · abstract:RESULTS: There was no significant difference in fractional calcium absorption from the two calcium-fortified[excerpt truncated in our database — see source]
                          • HumanShort-term dietary calcium fortification increases fecal saturated fat content and reduces serum lipids in men.
                            J Nutr, 1993 · Design: randomized · n: 13 healthy men · abstract only (PubMed) · open access (hybrid)
                            PMID 8505664DOI 10.1093/jn/123.6.1047
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:The effect of dietary calcium on fecal fatty acid excretion and serum lipids was tested in a randomized, single-blind metabolic study in 13 healthy men with moderate hypercholesterolemia.
                            • Key findings · abstract:The percentage of dietary saturated fat excreted per day increased from 6 to 13% with calcium fortification.
                            • Key findings · abstract:Urinary calcium excretion increased from 146 to 230 mg/d when the high Ca diet was consumed.
                            • Food effect · abstract:Fecal collections (72 h, d 8, 9, 10) and blood from fasting subjects for lipids and lipoproteins (d 9, 10, 11) were obtained.
                          • HumanCalcium bioavailability and its relation to osteoporosis.
                            Proc Soc Exp Biol Med, 1992 · Design: stable-isotope · abstract only (PubMed) · closed/paywalled
                            PMID 1579576DOI 10.3181/00379727-200-43409
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Milk calcium is usually the referent food which is typically absorbed at 20-40% depending on the calcium status of the subject.
                            • Fractional absorption · abstract:Milk calcium is usually the referent food which is typically absorbed at 20-40% depending on the calcium status of the subject.
                          • HumanNet calcium absorption in premature infants: results of 103 metabolic balance studies.
                            Am J Clin Nutr, 1992 · Design: not stated · n: 103 infants · abstract only (PubMed) · closed/paywalled
                            PMID 1307704DOI 10.1093/ajcn/56.6.1037
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Net calcium absorption was evaluated in 103 low-birth-weight preterm infants by a 72-h balance technique.
                            • Key findings · abstract:When tested 3 wk later, their net calcium absorption averaged 58 +/- 1% with an intake of 80 +/- 2 mg Ca.kg body wt-1.d-1.
                            • Key findings · abstract:Net calcium absorption was a linear function of intake (40-130 mg Ca.kg body wt-1.d-1) with a zero intercept.
                            • Food effect · abstract:Of the 103 infants, 58 had been fed low-birth-weight formulas supplemented with vitamin D.
                          • HumanCalcium and iron absorption: mechanism of action and nutritional importance.
                            Eur J Clin Nutr, 1992 · Design: clinical trial · abstract only (PubMed) · unknown
                            PMID 1600930
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:We investigated the inhibitory effect of calcium on iron absorption in 57 human subjects.
                            • Key findings · abstract:No inhibiting effect on iron absorption was seen when adding 3 mg calcium to 0.01 mg iron (molar ratio Ca/Fe = 420).
                            • Key findings · abstract:The practical nutritional implications of the inhibitory effect of calcium are considerable since addition of milk, milkshake or cheese to common meals such as pizza or hamburger meals reduced iron absorption by 50-60%.
                            • Food effect · abstract:The practical nutritional implications of the inhibitory effect of calcium are considerable since addition of milk, milkshake or cheese to common meals such as pizza or hamburger meals reduced iron absorption by 50-60%.
                          • HumanHuman calcium absorption from whole-wheat products.
                            J Nutr, 1991 · Design: randomized; crossover · abstract only (PubMed) · open access (hybrid)
                            PMID 1941185DOI 10.1093/jn/121.11.1769
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:In the first study, fractional calcium absorption from leavened whole-wheat bread averaged 0.817 +/- 0.124.
                            • Key findings · abstract:By comparison, absorption from milk, ingested at a comparable load in the same women, averaged only 0.589 +/- 0.111.
                            • Key findings · abstract:When labeled bread was co-ingested with milk, at the same aggregate load as for bread alone, bread calcium absorption fell to 0.748 +/- 0.103 (P less than 0.05).
                            • Key findings · abstract:Calcium absorption from the cereal (0.223 +/- 0.046) was significantly less than from milk (0.375 +/- 0.072) (P less than 0.001).
                            • Key findings · abstract:When the two were co-fed at the same total load, milk calcium absorption fe[excerpt truncated in our database — see source]
                            • Food effect · abstract:When the two were co-fed at the same total load, milk calcium absorption fell to 0.258 +/- 0.055 (P less than 0.001).
                          • HumanFluoride bioavailability from immediate-release sodium fluoride with calcium carbonate compared with slow-release sodium fluoride with calcium citrate.
                            Bone Miner, 1991 · Design: not stated · abstract only (PubMed) · closed/paywalled
                            PMID 1912761DOI 10.1016/0169-6009(91)90090-m
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:The circadian variation in serum fluoride was compared between treatment with immediate-release sodium fluoride (IR-NaF) (30 mg) and calcium carbonate (500 mg calcium) and slow-release sodium fluoride (SR-NaF) (25 mg) and calcium citrate (400 mg calcium) in seven patients with postmenopausal osteoporosis maintained on long-term fluoride treatment.
                            • Key findings · abstract:During 12 h following a dose of SR-NaF, serum fluoride levels could be largely kept within the therapeutic window (believed to be 95-190 ng/ml or 5-10 mumol/l).
                            • Key findings · abstract:Compared to SR-NaF, IR-NaF caused a significantly higher peak fluoride concentration[excerpt truncated in our database — see source]
                            • AUC · abstract:Compared to SR-NaF, IR-NaF caused a significantly higher peak fluoride concentration in serum (322 vs. 158 ng/ml), and greater area under the curve (2269 vs. 1321 ng.h/ml) and urinary fluoride (6.72 vs. 3.80 mg/12 h).
                          • HumanAmlodipine: pharmacokinetic profile of a low-clearance calcium antagonist.
                            J Cardiovasc Pharmacol, 1991 · Design: not stated · abstract only (PubMed) · unknown
                            PMID 16296697
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Amlodipine is absorbed gradually after oral administration (peak plasma levels 6-12 h postdose) and has an absolute bioavailability of 64%.
                            • Fractional absorption · abstract:Amlodipine is absorbed gradually after oral administration (peak plasma levels 6-12 h postdose) and has an absolute bioavailability of 64%.
                          • HumanCalcium bioavailability from calcium fortified food products.
                            J Nutr Sci Vitaminol (Tokyo), 1991 · Design: not stated · abstract (PubMed); full-text PDF saved · open access (gold)
                            PMID 1765836DOI 10.3177/jnsv.37.319PDF
                            Verification: full-text auto-extracted verbatim snippets with location; needs human check
                            • Food effect · full text, p.4:um-fortified food products under study (orange juice OJ, milk M, soda S, and experimental cheese T) or a calcium carbonate plus vitamin D tablet (CC) with breakfast. The calcium sources used to fortify these food products were different. For example: S contained CaCO3+Ca gluconate , T contained Ca3PO4, OJ contained Ca citrate malate and the milk contained CaCO3. Supplemented calcium in experimenta
                            • Food effect · full text, p.9:um salts. N. Engl. J. Med., 317, 532-536. 13) Greger, J. L., Krzykowski, C. E., Khazen, R. R., and Krashol, C. L. (1987): Mineral utilization by rats fed various commercially available calcium supplements or milk. J. Nutr., 117, 717-724. 14) Recker, R. R., Bammi, A., Barger-Lux, M. J., and Heaney, P. R. (1988): Calcium absorbability from milk products, an imitation milk and calcium carbonate. Am.
                            • Form comparison · full text, p.4:um excretions were not found to be statistically significantly different, but fecal calcium tended to be lower when subjects consumed M, OJ, and S as compared to control, CC, and T (39 .4. 550, and 43.2% versus 50.1, 54.4, and 55.5%, respectively) . A few recently-published studies reported that the form of calcium in the orange juice used in this experiment J. Nutr, Sci. Vitaminol.
                            • Form comparison · full text, p.5:erage 30% better than milk calcium (17, 18). Another publication reported a significant increase in calcium absorption from calcium citrate malate as compared to calcium carbonate (19). In the present study these dramatic differences were not demonstrated, possibly because the calcium carbonate tablet used in this study was combined with vitamin D. Table 2 indicates urinary calcium excretion as a
                            • Form comparison · full text, p.6:al transit times were not found to be significantly different (Table 3). However, M consumption tended to result in the fastest fecal transit time as compared to self-selected diets, CC, S, OJ, and T (34.3 versus 50.4, 46.6, 44.8, 47.0, and 52.8h, respectively). Decreased fecal transit times have also been noted with J. Nutr. Sci. Vitaminol.
                          • HumanCalcium supplementation: effect on iron absorption.
                            Am J Clin Nutr, 1991 · Design: stable-isotope · abstract only (PubMed) · closed/paywalled
                            PMID 1984334DOI 10.1093/ajcn/53.1.106
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:The influence of calcium supplements on the absorption of dietary nonheme iron and of iron supplements was evaluated in 61 normal volunteer subjects by use of a double-radioisotope technique.
                            • Key findings · abstract:When taken without food, calcium carbonate did not inhibit the absorption of ferrous sulphate with doses of either 300 mg Ca and 37 mg Fe or 600 mg Ca and 18 mg Fe.
                            • Key findings · abstract:However, at the latter levels, calcium citrate and calcium phosphate reduced iron absorption significantly by 49% and 62%, respectively.
                            • Food effect · abstract:This inhibition was less pronounced from a meal of high iron availability and low calcium content (28%) than from a breakfast meal of low iron availability and high calcium content (55%).
                          • HumanSoybean phytate content: effect on calcium absorption.
                            Am J Clin Nutr, 1991 · Design: not stated · abstract only (PubMed) · closed/paywalled
                            PMID 2000830DOI 10.1093/ajcn/53.3.745
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Absorption of calcium from soybeans with low and high phytate contents, intrinsically labeled with 45Ca, was measured in 16 normal women and compared in 15 of these same subjects with absorption of calcium from labeled milk.
                            • Key findings · abstract:Fractional calcium absorption (+/- SD) from the high-phytate soybeans averaged 0.310 +/- 0.070; from the low phytate soybeans, 0.414 +/- 0.074; and from milk, 0.377 +/- 0.056.
                            • Key findings · abstract:The mean difference (+/- SEM) in fractional calcium absorption for the two phytate levels was 0.104 +/- 0.014 (P less than 0.001).
                          • HumanCalcium citrate markedly enhances aluminum absorption from aluminum hydroxide.
                            Am J Kidney Dis, 1991 · Design: crossover · abstract only (PubMed) · closed/paywalled
                            PMID 2042654DOI 10.1016/s0272-6386(12)80356-8
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Baseline urinary aluminum excretion was determined for 2 days; thereafter, subjects ingested aluminum hydroxide for 3 days.
                            • Key findings · abstract:Baseline urinary aluminum excretion was 0.02 +/- 0.004 (6.5 +/- 1.1 micrograms/g creatinine) and 0.03 +/- 0.005 mumol/mmol creatinine (7.4 +/- 1.3 micrograms/g creatinine).
                            • Key findings · abstract:On 3 consecutive days, urinary aluminum excretion levels were 11.1 +/- 3.23, 8.8 +/- 2.9, and 5.3 +/- 0.7 times greater during the administration of calcium citrate with aluminum hydroxide than with aluminum hydroxide alone.
                          • HumanCalcium absorption in elderly subjects on high- and low-fiber diets: effect of gastric acidity.
                            Am J Clin Nutr, 1991 · Design: not stated · abstract only (PubMed) · closed/paywalled
                            PMID 1852094DOI 10.1093/ajcn/53.6.1480
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:In control subjects calcium retention, measured in a whole-body counter, was 25.7 +/- 4.0% (mean +/- SD) with the low-fiber meal, 19.1 +/- 1.9% with the high-fiber meal (P less than 0.002 vs low fiber), and 18.9 +/- 3.3% with the high-fiber-plus-acid meal (P less than 0.002 vs low fiber, NS vs high fiber).
                            • Key findings · abstract:Calcium absorption in achlorhydric subjects was not different from control subjects: 26.2 +/- 8.0% with low fiber, 19.6 +/- 4.1% with high fiber (P less than 0.04 vs low fiber), and 21.0 +/- 5.8% with high fiber plus acid (P less than 0.04 vs low fiber, NS vs high fiber).
                            • Food effect · abstract:In nine normal, elderly control subjects and eight elderly subjects with achlorhydria, 47Ca was ingested with three test meals: a low-fiber meal (0.5 g dietary fiber), a high-fiber meal (10.5 g), and a high-fiber meal with 120 mL of 0.1 mol HC/L.
                            • Food effect · abstract:In control subjects calcium retention, measured in a whole-body counter, was 25.7 +/- 4.0% (mean +/- SD) with the low-fiber meal, 19.1 +/- 1.9% with the high-fiber meal (P less than 0.002 vs low fiber), and 18.9 +/- 3.3% with the high-fiber-plus-acid meal (P less than 0.002 vs low fiber, NS vs high fiber).
                          • HumanCalcium: effect of different amounts on nonheme- and heme-iron absorption in humans.
                            Am J Clin Nutr, 1991 · Design: not stated · abstract only (PubMed) · closed/paywalled
                            PMID 1984335DOI 10.1093/ajcn/53.1.112
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:We investigated the effect of calcium on iron absorption in 126 human subjects.
                            • Key findings · abstract:As little as 40 mg Ca added to 80 g flour reduced phytate degradation by 50%, thus increasing the phytate content of the rolls to levels interfering with iron absorption.
                            • Key findings · abstract:Iron absorption was reduced by 50-60% at doses of 300-600 mg Ca.
                            • Key findings · abstract:Giving 165 mg Ca as milk, cheese, or calcium chloride reduced absorption by 50-60%.
                          • HumanCalcium absorption in normal and osteoporotic postmenopausal women.
                            Calcif Tissue Int, 1991 · Design: not stated · abstract only (PubMed) · closed/paywalled
                            PMID 1760766DOI 10.1007/BF02556211
                            Verification: abstract-only auto-extract; unverified
                            • Key findings · abstract:Hourly fractional absorption of radiocalcium (alpha), serum calcitriol, and a number of other variables were measured in 152 normal and 148 osteoporotic postmenopausal women.
                            • Key findings · abstract:The serum calcitriol level was slightly but not significantly lower in the osteoporotic than in the normal group and accounted for only 20% of the difference in alpha between them.
                            • Fractional absorption · abstract:Hourly fractional absorption of radiocalcium (alpha), serum calcitriol, and a number of other variables were measured in 152 normal and 148 osteoporotic postmenopausal women.
                          • Human[Combined administration of calcium and citrate reduces urinary oxalate excretion].
                            Hinyokika Kiyo, 1991 · Design: not stated · abstract only (PubMed) · unknown
                            PMID 1755399
                            Verification: abstract-only auto-extract; unverified
                            • HumanFluoride bioavailability from slow-release sodium fluoride given with calcium citrate.
                              J Bone Miner Res, 1990 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 2239370DOI 10.1002/jbmr.5650050809
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Following a single oral administration of 50 mg slow-release sodium fluoride, a peak serum fluoride concentration (Cmax) of 184 ng/ml was reached in 2 h; thereafter, serum fluoride concentration declined with a T1/2 of 5.9 h.
                              • Key findings · abstract:The concurrent administration of calcium citrate (400 mg calcium) gave an equivalent Tmax (time required to attain Cmax) and T1/2, but a lower Cmax of 135 ng/ml.
                              • Key findings · abstract:The area under the serum concentration curve of slow-release sodium fluoride was reduced 17-27% by a meal or calcium citrate.
                              • Key findings · abstract:During long-term administration of 25 mg slow-release sodium fluoride coadminist[excerpt truncated in our database — see source]
                              • Cmax · abstract:Following a single oral administration of 50 mg slow-release sodium fluoride, a peak serum fluoride concentration (Cmax) of 184 ng/ml was reached in 2 h; thereafter, serum fluoride concentration declined with a T1/2 of 5.9 h.
                              • Cmax · abstract:The concurrent administration of calcium citrate (400 mg calcium) gave an equivalent Tmax (time required to attain Cmax) and T1/2, but a lower Cmax of 135 ng/ml.
                              • Tmax · abstract:The concurrent administration of calcium citrate (400 mg calcium) gave an equivalent Tmax (time required to attain Cmax) and T1/2, but a lower Cmax of 135 ng/ml.
                              • AUC · abstract:The area under the serum concentration curve of slow-release sodium fluoride was reduced 17-27% by a meal or calcium citrate.
                              • Food effect · abstract:The area under the serum concentration curve of slow-release sodium fluoride was reduced 17-27% by a meal or calcium citrate.
                            • HumanEffects of different calcium sources on iron absorption in postmenopausal women.
                              Am J Clin Nutr, 1990 · Design: clinical trial · abstract only (PubMed) · closed/paywalled
                              PMID 2296934DOI 10.1093/ajcn/51.1.95
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:We measured the effect of calcium from food and supplement sources on whole-body retention of 59Fe in 19 normal postmenopausal women.
                              • Key findings · abstract:Retention of 59Fe was 8.3 +/- 1.1% (means +/- SEM) with placebo, 3.4 +/- 0.78% with milk, 6.0 +/- 0.97% with CCM, and 7.4 +/- 1.7% with CCM plus orange juice.
                              • Key findings · abstract:When compared with placebo, milk and CCM significantly lowered iron retention (p less than 0.05) whereas CCM plus orange juice did not.
                              • Key findings · abstract:The reduction with milk was greater than that with CCM (p less than 0.05) or CCM plus orange juice (p less than 0.05).
                              • Key findings · abstract:The differences in the effects of these calc[excerpt truncated in our database — see source]
                              • Food effect · abstract:Each woman received a placebo and 500 mg calcium from a mixed calcium citrate-malate salt (CCM), from orange juice plus CCM, and from milk after a test breakfast meal to which 59Fe had been added.
                              • Food effect · abstract:The test meal contained 238 mg calcium.
                              • Food effect · abstract:Whole-body countings of 59Fe were performed before and 30 min and 2 wk after each test meal.
                            • HumanCalcium absorption from kale.
                              Am J Clin Nutr, 1990 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 2321572DOI 10.1093/ajcn/51.4.656
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Absorption of calcium from intrinsically labeled kale was measured in 11 normal women and compared in these same subjects with absorption of calcium from labeled milk.
                              • Key findings · abstract:Fractional calcium absorption from kale averaged 0.409 +/- 0.101 (means +/- SD) and from milk, 0.321 +/- 0.089 (P less than 0.025).
                            • HumanSuperior calcium absorption from calcium citrate than calcium carbonate using external forearm counting.
                              J Am Coll Nutr, 1990 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 2273192DOI 10.1080/07315724.1990.10720413
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Calcium absorption from calcium citrate was compared with that obtained from calcium carbonate in 20 normal women.
                              • Key findings · abstract:It was measured by external forearm counting technique, where the ratio of forearm radioactivity after an oral dose of labeled calcium salt (containing 500 mg calcium) and after an intravenous injection of trace radiocalcium represented fractional calcium absorption.
                              • Key findings · abstract:The fractional calcium absorption from calcium citrate was 39.2 +/- 8.6%, which was significantly higher than the 31.2 +/- 9.4% derived from calcium carbonate (p less than 0.001).
                            • HumanCalcium supplementation lowers serum parathyroid hormone levels in elderly subjects.
                              J Gerontol, 1990 · Design: randomized; crossover; double-blind · n: 40 healthy volunteers · abstract only (PubMed) · closed/paywalled
                              PMID 2203847DOI 10.1093/geronj/45.5.m159
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Calcium supplementation (1000 mg/day) decreased serum PTH levels from a mean of 50.1 +/- 3.0 pg/ml to 41.9 +/- 2.4 pg/ml (p less than .001).
                              • Key findings · abstract:Additionally, urine calcium excretion significantly increased during calcium administration (from 3.64 mmol/mmol creatinine at baseline to 4.28 mmol/mmol creatinine), but creatinine clearances and serum calcium levels remained unchanged.
                              • Food effect · abstract:Fasting blood samples and 24-hour urine collections were obtained at baseline, and at the end of each intervention period.
                            • HumanInfluence of calcium load on absorption fraction.
                              J Bone Miner Res, 1990 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 2270776DOI 10.1002/jbmr.5650051107
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:True calcium absorption was studied as a function of the size of the ingested load in healthy adult women, under meal conditions and at loads ranging from 15 to 500 mg calcium.
                              • Key findings · abstract:Fractional absorption was highly inversely correlated with the logarithm of load (P less than 0.001).
                              • Key findings · abstract:At the lowest loads, absorption averaged 64.0% and at the highest, 28.6%.
                              • Fractional absorption · abstract:Fractional absorption was highly inversely correlated with the logarithm of load (P less than 0.001).
                              • Food effect · abstract:True calcium absorption was studied as a function of the size of the ingested load in healthy adult women, under meal conditions and at loads ranging from 15 to 500 mg calcium.
                            • HumanIntestinal oxalate and calcium absorption in recurrent renal stone formers and healthy subjects.
                              Scand J Urol Nephrol, 1989 · Design: stable-isotope · abstract only (PubMed) · closed/paywalled
                              PMID 2922580DOI 10.1080/00365599.1989.11690431
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:The fractional intestinal absorption of oxalate and calcium was investigated by isotope techniques in 20 normal subjects and in 12 idiopathic calcium oxalate stone formers.
                              • Key findings · abstract:The greatest amount of 14C-oxalate was excreted during the first six hour period in controls as well as in stone formers.
                              • Key findings · abstract:The stone formers had a greater intestinal uptake of oxalate (11 +/- 5.1%) than the controls (6.2 +/- 3.7%; p less than 0.01).
                              • Key findings · abstract:The stone formers also had a higher fractional uptake of calcium compared to the controls (55 +/- 11% vs. 47 +/- 9.1%; p less than 0.05).
                              • Key findings · abstract:There was a positive relationshi[excerpt truncated in our database — see source]
                            • HumanCalcium absorption in children estimated from single and double stable calcium isotope techniques.
                              Clin Chim Acta, 1989 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 2791301DOI 10.1016/0009-8981(89)90326-4
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:High-resolution, fast atom bombardment mass spectrometry was used to quantify the 44Ca and 42Ca tracers in serum and urine.
                              • Key findings · abstract:The average calcium absorption estimated from the ratio of urinary tracers was 41.4 +/- 8.2%.
                              • Key findings · abstract:This study indicates that the level of oral tracer in serum taken 150 min post-ingestion is significantly correlated (r = 0.85, p less than 0.05) with calcium absorption, as determined by the tracer levels in the urine.
                              • Food effect · abstract:Subjects ingested 250 mg of calcium (215 mg calcium enriched with 35 mg 44Ca) in the form of a chewable calcium citrate malate tablet with a standard meal, followed 30 min later with an i.v. injection of 42Ca tracer.
                            • HumanCalcium absorption from milk in lactase-deficient subjects.
                              Am J Clin Nutr, 1989 · Design: randomized; stable-isotope · abstract only (PubMed) · closed/paywalled
                              PMID 2492746DOI 10.1093/ajcn/49.2.377
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:With (-), Ca absorption was identical in NL and LD subjects and slightly higher than with water solution (15%, NS).
                              • Key findings · abstract:With (+), Ca absorption in NL subjects was identical with that from water solution; in LD subjects it increased (23%, p less than 0.02).
                            • HumanCalcium absorption in women: relationships to calcium intake, estrogen status, and age.
                              J Bone Miner Res, 1989 · Design: stable-isotope · abstract only (PubMed) · closed/paywalled
                              PMID 2816496DOI 10.1002/jbmr.5650040404
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:A total of 526 absorption studies, using both the double-isotope and balance-based methods, were performed in 189 middle-aged women in good general health.
                              • Key findings · abstract:Mean absorption fraction declined from a value of 0.45 at very low intakes (approximately 200 mg Ca per day) to approximately 0.15 at intakes above 2000 mg/day.
                              • Key findings · abstract:There was a highly significant fall in absorption efficiency with age, amounting to approximately 0.0021 per year and a one-time decrease, amounting to approximately 0.022 at the time of menopausal estrogen loss.
                            • HumanOxalate: effect on calcium absorbability.
                              Am J Clin Nutr, 1989 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 2801588DOI 10.1093/ajcn/50.4.830
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Absorption of calcium from intrinsically labeled Ca oxalate was measured in 18 normal women and compared with absorption of Ca from milk in these same subjects, both when the test substances were ingested in separate meals and when ingested together.
                              • Key findings · abstract:Fractional Ca absorption from oxalate averaged 0.100 +/- 0.043 when ingested alone and 0.140 +/- 0.063 when ingested together with milk.
                              • Key findings · abstract:Absorption was, as expected, substantially lower than absorption from milk (0.358 +/- 0.113).
                              • Food effect · abstract:Absorption of calcium from intrinsically labeled Ca oxalate was measured in 18 normal women and compared with absorption of Ca from milk in these same subjects, both when the test substances were ingested in separate meals and when ingested together.
                            • HumanDose dependency of calcium absorption: a comparison of calcium carbonate and calcium citrate.
                              J Bone Miner Res, 1988 · Design: not stated · n: 4 men · abstract only (PubMed) · closed/paywalled
                              PMID 3213620DOI 10.1002/jbmr.5650030303
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Using the well-described oral calcium load technique, we measured the calcium absorption from three different calcium doses (0.5, 1.0, and 2.0 g) of both calcium carbonate and calcium citrate administered to 21 normal subjects (4 men and 17 women, 22-60 years).
                              • Key findings · abstract:The increment in urinary calcium post-load, reflective of intestinal calcium absorption, rose rapidly from 0 to 0.5 g calcium loads with only slight subsequent increases from the 0.5 g to 2.0 g calcium doses.
                              • Key findings · abstract:The increment in urinary calcium (during the second 2 hr) following calcium citrate load (0.5 g calcium) was 0.104 +/- 0.096[excerpt truncated in our database — see source]
                            • HumanCalcium absorbability from spinach.
                              Am J Clin Nutr, 1988 · Design: randomized; crossover; stable-isotope · n: 13 healthy adults · abstract only (PubMed) · closed/paywalled
                              PMID 3354496DOI 10.1093/ajcn/47.4.707
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:The absorbability of calcium from spinach was compared with the absorbability of Ca from milk in 13 healthy adults in a randomized cross-over design in which the test meal of either milk or spinach had 200 mg of Ca labeled with 45Ca.
                              • Key findings · abstract:Absorption was higher from milk in every case, with the mean absorption from milk averaging 27.6% and from spinach, 5.1%.
                              • Key findings · abstract:The mean within-subject difference between Ca absorption from milk and from spinach was 22.5 +/- 9.5% (P less than 0.0001).
                              • Food effect · abstract:The absorbability of calcium from spinach was compared with the absorbability of Ca from milk in 13 healthy adults in a randomized cross-over design in which the test meal of either milk or spinach had 200 mg of Ca labeled with 45Ca.
                            • HumanCalcium absorption from calcium carbonate and a new form of calcium (CCM) in healthy male and female adolescents.
                              Am J Clin Nutr, 1988 · Design: randomized; crossover · abstract only (PubMed) · closed/paywalled
                              PMID 3189218DOI 10.1093/ajcn/48.5.1291
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Calcium absorption from two Ca salts was investigated in a crossover design using stable isotopic tracers in 12 healthy adolescents (6 males, 6 females).
                              • Key findings · abstract:The molar concentrations of 42Ca and 44Ca tracers in a urine sample obtained 24 h after tracer administration were quantified by fast-atom-bombardment mass spectrometry and used to determine fractional absorption of the Ca from the supplement.
                              • Key findings · abstract:Ca in the form of CCM had an increased fractional absorption (p less than 0.03) relative to Ca carbonate in healthy adolescents (36.2 vs 26.4%).
                              • Fractional absorption · abstract:The molar concentrations of 42Ca and 44Ca tracers in a urine sample obtained 24 h after tracer administration were quantified by fast-atom-bombardment mass spectrometry and used to determine fractional absorption of the Ca from the supplement.
                              • Fractional absorption · abstract:Ca in the form of CCM had an increased fractional absorption (p less than 0.03) relative to Ca carbonate in healthy adolescents (36.2 vs 26.4%).
                            • HumanVariability of calcium absorption.
                              Am J Clin Nutr, 1988 · Design: stable-isotope · n: 22 subjects · abstract only (PubMed) · closed/paywalled
                              PMID 3341257DOI 10.1093/ajcn/47.2.262
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Variability in calcium absorption was estimated in three groups of normal subjects in whom Ca absorption was measured by standard isotopic-tracer methods at interstudy intervals ranging from 1 to 4 mo.
                              • Key findings · abstract:Fifty absorption tests were performed in 22 subjects.
                              • Key findings · abstract:The coefficient of variation (CVs) for absorption for the three groups ranged from 10.57 to 12.79% with the size of the CV increasing with interstudy duration.
                              • Key findings · abstract:One other published study presenting replicate absorption values was analyzed in a similar fashion and was found to have a CV of absorption of 9.78%.
                              • Key findings · abstract:From these data we estimat[excerpt truncated in our database — see source]
                              • Food effect · abstract:Each was done in the morning after an overnight fast with an identical standard breakfast containing a Ca load of approximately 250 mg.
                            • HumanMeasurement of true calcium absorption in premature infants using intravenous 46Ca and oral 44Ca.
                              Pediatr Res, 1988 · Design: stable-isotope · abstract only (PubMed) · closed/paywalled
                              PMID 3393391DOI 10.1203/00006450-198806000-00012
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:We have developed a method for measuring true fractional calcium absorption (alpha) in premature infants using two stable isotopes of calcium and tested it in seven studies in seven infants (birth weight 1543 +/- 65 g, gestation 32.8 +/- 7 wk).
                              • Key findings · abstract:Percent absorption (alpha) equals a constant times cumulative delta % excess 44Ca/delta % excess 46Ca.
                              • Key findings · abstract:These values are somewhat higher than net percent calcium absorption values reported for standard formula and thus appear very appropriate.(ABSTRACT TRUNCATED AT 250 WORDS)
                            • HumanCalcium absorption: effect of meal and glucose polymer.
                              Am J Clin Nutr, 1988 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 3407610DOI 10.1093/ajcn/48.2.312
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Using a single-day method, we measured net Ca absorption from Ca carbonate when ingested in fasting state, with a steak and potatoes meal, and with the meal and 50 g glucose polymer.
                              • Key findings · abstract:Mean net Ca absorption was 195 +/- 18 mg (4.87 +/- 0.45 mmol) fasting, 213 +/- 21 mg (5.31 +/- 0.52 mmol) with a meal, and 179 +/- 16 mg (4.47 +/- 0.40 mmol) with a meal plus glucose polymer.
                              • Key findings · abstract:In normal people Ca absorption from Ca carbonate was not significantly enhanced by a meal or by 50 g glucose polymer ingested with food.
                              • Food effect · abstract:Using a single-day method, we measured net Ca absorption from Ca carbonate when ingested in fasting state, with a steak and potatoes meal, and with the meal and 50 g glucose polymer.
                              • Food effect · abstract:Mean net Ca absorption was 195 +/- 18 mg (4.87 +/- 0.45 mmol) fasting, 213 +/- 21 mg (5.31 +/- 0.52 mmol) with a meal, and 179 +/- 16 mg (4.47 +/- 0.40 mmol) with a meal plus glucose polymer.
                              • Food effect · abstract:In normal people Ca absorption from Ca carbonate was not significantly enhanced by a meal or by 50 g glucose polymer ingested with food.
                            • HumanEnhanced calcium bioavailability from a solubilized form of calcium citrate.
                              J Clin Endocrinol Metab, 1987 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 3654922DOI 10.1210/jcem-65-4-801
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Intestinal calcium absorption, measured from the increment in urinary calcium during the second 2 h following an oral calcium load (500 mg) in 15 normal subjects was significantly higher from the mixtures (calcium to citrate molar ratios of 1.5 and 1.25) than from tricalcium dicitrate.
                              • Key findings · abstract:The fractional calcium absorption, obtained from fecal recovery of radiocalcium after oral administration of 500 mg calcium prelabeled with 47Ca in 11 normal subjects, was also higher for the mixture with a calcium to citrate molar ratio of 1.25.
                              • Key findings · abstract:The most efficient calcium absorption was obtained with the mi[excerpt truncated in our database — see source]
                            • HumanGastrointestinal absorption of calcium from milk and calcium salts.
                              N Engl J Med, 1987 · Design: randomized · abstract only (PubMed) · closed/paywalled
                              PMID 3614304DOI 10.1056/NEJM198708273170903
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Using a method by which the net absorption of calcium can be accurately measured after a single dose, we studied eight healthy fasting subjects after they took a 500-mg dose of calcium from each of five calcium salts with various degrees of water solubility and from milk.
                              • Key findings · abstract:The mean (+/- SEM) net calcium absorption, in decreasing order of the solubility of the salts, was 32 +/- 4 percent from calcium acetate, 32 +/- 4 percent from calcium lactate, 27 +/- 3 percent from calcium gluconate, 30 +/- 3 percent from calcium citrate, and 39 +/- 3 percent from calcium carbonate.
                              • Key findings · abstract:Calcium absorption fr[excerpt truncated in our database — see source]
                              • Food effect · abstract:Using a method by which the net absorption of calcium can be accurately measured after a single dose, we studied eight healthy fasting subjects after they took a 500-mg dose of calcium from each of five calcium salts with various degrees of water solubility and from milk.
                            • HumanCalcium bioavailability from calcium carbonate and calcium citrate.
                              J Clin Endocrinol Metab, 1985 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 4008614DOI 10.1210/jcem-61-2-391
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:The urinary calcium following calcium citrate load significantly higher (by 20-66%), whether expressed as the total amount or as the increment above basal (fasting) excretion.
                              • Food effect · abstract:The urinary calcium following calcium citrate load significantly higher (by 20-66%), whether expressed as the total amount or as the increment above basal (fasting) excretion.
                            • HumanCalcium absorption and achlorhydria.
                              N Engl J Med, 1985 · Design: stable-isotope · abstract only (PubMed) · closed/paywalled
                              PMID 4000241DOI 10.1056/NEJM198507113130202
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:I compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects.
                              • Key findings · abstract:Fractional calcium absorption was measured by a modified double-isotope procedure with 0.25 g of calcium used as the carrier.
                              • Key findings · abstract:Mean calcium absorption (+/- S.D.) in the patients with achlorhydria was 0.452 +/- 0.125 for citrate and 0.042 +/- 0.021 for carbonate (P less than 0.0001).
                              • Key findings · abstract:Fractional calcium absorption in the normal subjects was 0.243 +/- 0.049 for citrate and 0.225 +/- 0.108 for carbonate (not signif[excerpt truncated in our database — see source]
                              • Food effect · abstract:I compared absorption of calcium in its carbonate form with that in a pH-adjusted citrate form in a group of 11 fasting patients with achlorhydria and in 9 fasting normal subjects.
                            • HumanCalcium absorption in rheumatoid arthritis.
                              Ann Rheum Dis, 1985 · Design: stable-isotope · abstract only (PubMed) · open access (bronze)
                              PMID 3876078DOI 10.1136/ard.44.9.585PMC1001714 (free full text)
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Calcium absorption, assessed by a double isotope method, was found to be impaired in postmenopausal women with rheumatoid arthritis of recent onset (mean 14.2 months) compared with controls.
                              • Key findings · abstract:Circulating levels of 1,25-dihydroxyvitamin D (calcitriol) were higher than in controls, suggesting a primary malabsorption of calcium in these patients.
                            • HumanEstimation of true calcium absorption.
                              Ann Intern Med, 1985 · Design: stable-isotope · abstract only (PubMed) · closed/paywalled
                              PMID 4037557DOI 10.7326/0003-4819-103-4-516
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:True absorption, body size, and miscible pool turnover could together explain better than 93% of the variance in serum calcium specific activity values 5 hours after a tracer-labeled test meal.
                              • Key findings · abstract:Because measurement of pool turnover is not available routinely, it was dropped from the model, and a predictor equation was developed that allowed estimation of true absorption from the 5-hour serum specific activity value, height, and weight.
                              • Key findings · abstract:These variables explained 90.8% of the variance in the 5-hour values and gave estimates of true absorption with a 95% confidence interval of +/- 0.055.
                              • Food effect · abstract:True absorption, body size, and miscible pool turnover could together explain better than 93% of the variance in serum calcium specific activity values 5 hours after a tracer-labeled test meal.
                            • HumanEffect of phosphate supplementation to breast fed very low birthweight infants on urinary calcium excretion, serum immunoreactive parathyroid hormone and plasma 1,25-dihydroxy-vitamin D concentration.
                              Acta Paediatr Scand, 1985 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 3840317DOI 10.1111/j.1651-2227.1985.tb10009.x
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:The concentration of calcium and phosphorus in serum and urine, the serum concentration of immunoreactive parathyroid hormone (iPTH) and the plasma 1,25-dihydroxy-vitamin D concentration (1,25-OH-D) were compared to the values in 19 control infants.
                              • Key findings · abstract:The mean +/- SD concentrations in control infants and adults are 63 +/- 18 microliters Eq/ml for serum iPTH and 85 +/- pmol/l for plasma 1,25-OH-D.
                              • Key findings · abstract:With 0.48 P supplementation, urinary Ca (UCa) excretion (median and range) 0.238 mmol/kg/24 h (0.105-0.520) was lower than in the control group 0.288 (0.205-0.679) (p less than 0.05); the reduction[excerpt truncated in our database — see source]
                              • Food effect · abstract:These data show that with 0.8 P supplementation, the hypercalciuria in BM-fed infant disappears without secondary hyperparathyroidism, but without any change in plasma 1,25-OH-D concentration.
                            • HumanAn evaluation of the importance of gastric acid secretion in the absorption of dietary calcium.
                              J Clin Invest, 1984 · Design: not stated · abstract only (PubMed) · open access (bronze)
                              PMID 6707197DOI 10.1172/JCI111254PMC425063 (free full text)
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Since calcium solubility is a prerequisite to calcium absorption, and since solubility of calcium is highly pH-dependent, it has been generally assumed that gastric acid secretion and gastric acidity play an important role in the intestinal absorption of calcium from ingested food or calcium salts such as CaCO3.
                              • Key findings · abstract:Moreover, calcium absorption after CaCO3 ingestion was the same when intragastric contents were maintained at pH 7.4 (by in vivo titration) as when intragastric pH was 3.0.
                            • HumanA comparison of radioactive calcium absorption tests with net calcium absorption.
                              Clin Sci (Lond), 1981 · Design: stable-isotope · n: 71 patients · abstract only (PubMed) · closed/paywalled
                              PMID 7285497DOI 10.1042/cs0610477
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Four different methods of calculating calcium absorption by radioactive calcium procedures have been compared with each other and with net calcium absorption in calcium-balance studies in 100 consecutive studies on 71 patients. 2.
                              • Key findings · abstract:All four isotope procedures yielded highly significant correlations with net calcium absorption derived from the balance studies, but there was little to choose between the validity of the double-isotope and single-isotope procedure judged by these criteria. 3.
                              • Key findings · abstract:The rate of calcium absorption calculated from one or other isotope procedure correlated better with ne[excerpt truncated in our database — see source]
                              • Fractional absorption · abstract:The rate of calcium absorption calculated from one or other isotope procedure correlated better with net calcium absorption than did the fraction of the radioactive calcium absorbed. 4.
                            • HumanIntestinal calcium absorption in exogenous hypercortisonism. Role of 25-hydroxyvitamin D and corticosteroid dose.
                              J Clin Invest, 1977 · Design: stable-isotope · n: 27 patients · abstract only (PubMed) · open access (bronze)
                              PMID 874087DOI 10.1172/JCI108762PMC372363 (free full text)
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:However, the relationship between the impaired calcium absorption and a possible defect in the conversion of vitamin D to its physiologically active form, 1,25-dihydroxyvitamin D, is unknown.
                              • Key findings · abstract:We compared fractional calcium absorption (double-isotope method, 100-mg carrier) and serum 25-hydroxyvitamin D (25-OH-D) (Haddad method) in 27 patients receiving pharmacologic doses of prednisone with 27 age-, sex-, and season-matched normal subjects.
                              • Key findings · abstract:In patients receiving high daily doses of prednisone (15-100 mg/day), calcium absorption (P < 0.02) and serum 25-OH-D (P < 0.001) were decreased.
                              • Key findings · abstract:Cal[excerpt truncated in our database — see source]
                            • HumanCalcium absorption in Crohn's disease.
                              Gastroenterology, 1976 · Design: stable-isotope · n: 31 patients · abstract only (PubMed) · unknown
                              PMID 939386
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Calcium malabsorption resulting in negative calcium balance was found in only 4 of 31 patients with Crohn's disease.
                              • Key findings · abstract:No elevation of endogenous fecal calcium or total secreted intestinal calcium was observed in 10 patients studied, regardless of the level of net or true calcium absorption.
                            • HumanCalcium absorption as a function of calcium intake.
                              J Lab Clin Med, 1975 · Design: stable-isotope · n: 14 subjects · abstract only (PubMed) · unknown
                              PMID 1138021
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:The relationships between the amount of calcium absorbed and the quantity ingested was evaluated in 180 adult humans.
                              • Key findings · abstract:Absorption (Ca Abs) was found to follow a curvillnear relationship with intake (Ca-D), and was characterized by the following equation: Ca Abs equals 0.1541 - Ca-D plus 0.3127[exp(-1.0539 - Ca-D)] - Ca-D.
                              • Key findings · abstract:The exponential term of this equation provided the major component of total absorption at intakes below 0.8 Gm. per day, but fell to negligible values when intake reached 2 to 3 Gm. per day, above which absorption was characterized by a simple linear function of intake.
                              • Fractional absorption · abstract:The relationships between the amount of calcium absorbed and the quantity ingested was evaluated in 180 adult humans.
                            • RodentBone composition and histology of young growing rats fed diets of varied calcium bioavailability: spinach, nonfat dry milk, or calcium carbonate added to casein.
                              J Nutr, 1992 · Design: not stated · abstract only (PubMed) · closed/paywalled
                              PMID 1729463DOI 10.1093/jn/122.1.137
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:In contrast, when calcium is fed to growing animals at levels below the National Research Council requirement but from a highly bioavailable source (i.e., NFDM and CaCO3), there is only a reduction in bone quantity.
                              • Food effect · abstract:Bone composition and histology were evaluated in young growing rats fed nutritionally complete but calcium-restricted (0.15%) diets in which calcium was derived from spinach, nonfat dry milk (NFDM), or CaCO3 added to casein.
                              • Food effect · abstract:Groups of male weanling rats were pair-fed for 28 d.
                              • Food effect · abstract:A 0.5% calcium casein-based diet group fed ad libitum was included to provide a comparison of normal bone structure and composition.
                              • Food effect · abstract:In contrast, when calcium is fed to growing animals at levels below the National Research Council requirement but from a highly bioavailable source (i.e., NFDM and CaCO3), there is on
                            • Other animalSolubility and bioavailability of stabilized amorphous calcium carbonate.
                              J Bone Miner Res, 2011 · Design: not stated · abstract only (PubMed) · open access (bronze)
                              PMID 20690187DOI 10.1002/jbmr.196
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:Since its role in the prevention of osteoporosis in humans was proven some 30 years ago, calcium bioavailability has been the subject of numerous scientific studies.
                              • Key findings · abstract:Fractional absorption was evaluated by intrinsically labeling calcium carbonate preparations with (45)Ca, orally administrated to rats using gelatin capsules.
                              • Key findings · abstract:Fractional absorption was determined by evaluating the percentage of the administrated radioactive dose per milliliter that was measured in the serum, calcium absorption in the femur, and whole-body retention over a 34-hour period.
                              • Key findings · abstract:Calcium serum analysis revealed that[excerpt truncated in our database — see source]
                              • Fractional absorption · abstract:Fractional absorption was evaluated by intrinsically labeling calcium carbonate preparations with (45)Ca, orally administrated to rats using gelatin capsules.
                              • Fractional absorption · abstract:Fractional absorption was determined by evaluating the percentage of the administrated radioactive dose per milliliter that was measured in the serum, calcium absorption in the femur, and whole-body retention over a 34-hour period.
                              • Fractional absorption · abstract:Absorbed calcium in the femurs of ACC-administrated rats was 30% higher than in CCC-treated animals, whereas 15% more calcium was absorbed following ACC-C treatment than following CCC treatment.
                            • Other animalCalcium absorption from apple and orange juice fortified with calcium citrate malate (CCM).
                              J Am Coll Nutr, 1996 · Design: not stated · n: n = 57 · abstract only (PubMed) · closed/paywalled
                              PMID 8935449DOI 10.1080/07315724.1996.10718604
                              Verification: abstract-only auto-extract; unverified
                              • Key findings · abstract:METHODS: Absorbability was assessed by measuring 45Ca absorption in healthy women (mean age 57 years, n = 57/group) and whole body 47Ca retention in adult female beagle dogs (n = 6/group) and young adult male rats (n = 6/group).
                              • Key findings · abstract:Additional 47Ca whole body retention experiments in rats measured the effects of differences in the carbohydrate and organic acid contents of the juices on Ca absorption.
                              • Key findings · abstract:RESULTS: Mean +/- SEM percent Ca fractional absorption was greater (p < 0.003) in women who consumed CCM-AJ (42 +/- 2%) than those who consumed CCM-OJ (36 +/- 1%).
                              • Fractional absorption · abstract:RESULTS: Mean +/- SEM percent Ca fractional absorption was greater (p < 0.003) in women who consumed CCM-AJ (42 +/- 2%) than those who consumed CCM-OJ (36 +/- 1%).

                            Reviewer

                            Dr. Colin Reily, PhD

                            PhD, molecular pathology & biochemistry. Reviews the science and evidence (not medical advice).

                            Draft, pending sign-off Next review: set at sign-off

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