{"built_at":"2026-10-31","supplements":[{"slug":"magnesium","name":"Magnesium","rank":2,"studyCount":171,"speciesCounts":{"human":85,"pig":3,"rodent":48,"other_animal":32,"unclear":3},"grade":"B","forms":["glycinate","citrate","oxide","malate","threonate","chloride","taurate","sulfate","lactate","aspartate","orotate","carbonate","pidolate"],"evidence_grade":"B","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Magnesium","papers":83,"withData":81,"pkValues":869,"species":{"human":37,"rodent":29,"other_animal":12,"pig":1,"in_vitro":1,"unclear":1},"pairs":{"glycinate-vs-citrate":["B","1 human studies (1 randomized/crossover); majority: second form higher (1 agree, 0 contradict)"],"citrate-vs-oxide":["B","1 human studies (1 randomized/crossover); majority: no significant difference (1 agree, 0 contradict)"],"glycinate-vs-oxide":["C","3 human studies (2 randomized/crossover); majority: second form higher (1 agree, 1 contradict)"],"citrate-vs-chloride":[null,"no direct comparison in extracted data"],"citrate-vs-lactate":[null,"no direct comparison in extracted data"],"oxide-vs-chloride":[null,"no direct comparison in extracted data"],"aspartate-vs-oxide":[null,"no direct comparison in extracted data"]},"indirect_unavailable":[["glycinate vs citrate","no matched condition set: arms differ on PK parameter"],["glycinate vs oxide","all arms come from the same studies (head-to-head only, see above)"],["citrate vs oxide","no matched condition set: arms differ on matrix"],["citrate vs chloride","all arms come from the same studies (head-to-head only, see above)"],["citrate vs lactate","no matched condition set: arms differ on matrix"],["oxide vs chloride","no matched condition set: arms differ on units"],["oxide vs aspartate","no human single-form arm with a printed value for Aspartate"]],"indirect":[["oxide-vs-lactate",null,2,null],["chloride-vs-lactate",null,2,null]]},"page_url":"https://supplementabsorption.com/magnesium"},{"slug":"iron","name":"Iron","rank":18,"studyCount":222,"speciesCounts":{"human":222},"grade":"B","forms":["ferrous-sulfate","bisglycinate","fumarate","gluconate","polysaccharide","heme"],"evidence_grade":"A","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Iron","papers":116,"withData":109,"pkValues":1921,"species":{"human":80,"in_vitro":28,"other_animal":1},"pairs":{"bisglycinate-vs-ferrous-sulfate":[null,"no direct comparison in extracted data"]},"indirect_unavailable":[],"indirect":[["ferrous-sulfate-vs-bisglycinate","D",1,null],["ferrous-sulfate-vs-fumarate",null,2,null],["ferrous-sulfate-vs-heme","D",2,null]]},"page_url":"https://supplementabsorption.com/iron"},{"slug":"curcumin","name":"Curcumin (Turmeric)","rank":9,"studyCount":186,"speciesCounts":{"human":102,"rodent":17,"other_animal":67},"grade":"B","forms":["piperine","phytosome","nanoparticle","micellar"],"evidence_grade":"B","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Curcumin (Turmeric)","papers":105,"withData":89,"pkValues":1636,"species":{"rodent":48,"in_vitro":18,"human":16,"other_animal":7},"pairs":{},"indirect_unavailable":[],"indirect":[["piperine-vs-phytosome","D",2,null]]},"page_url":"https://supplementabsorption.com/curcumin"},{"slug":"vitamin-d","name":"Vitamin D","rank":1,"studyCount":204,"speciesCounts":{"human":136,"primate":1,"pig":4,"rodent":13,"other_animal":40,"in_vitro":2,"unclear":8},"grade":"B","forms":["d3","d2","calcifediol"],"evidence_grade":"A","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Vitamin D","papers":108,"withData":91,"pkValues":489,"species":{"human":54,"rodent":23,"in_vitro":10,"other_animal":4},"pairs":{"d3-vs-d2":["C","4 human studies (2 randomized/crossover); majority: first form higher (2 agree, 1 contradict)"]},"indirect_unavailable":[["d3 vs d2","matched only within the same study"]],"indirect":[]},"page_url":"https://supplementabsorption.com/vitamin-d"},{"slug":"coq10","name":"Coenzyme Q10","rank":8,"studyCount":114,"speciesCounts":{"human":59,"pig":3,"rodent":4,"other_animal":36,"in_vitro":2,"unclear":10},"grade":"B","forms":["ubiquinone","ubiquinol","solubilized"],"evidence_grade":"B","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Coenzyme Q10","papers":67,"withData":59,"pkValues":522,"species":{"human":29,"rodent":19,"other_animal":6,"in_vitro":5},"pairs":{"ubiquinol-vs-ubiquinone":["B","1 human studies (1 randomized/crossover); majority: first form higher (1 agree, 0 contradict)"]},"indirect_unavailable":[["ubiquinone vs ubiquinol","no human single-form arm with a printed value for Ubiquinone"]],"indirect":[]},"page_url":"https://supplementabsorption.com/coq10"},{"slug":"zinc","name":"Zinc","rank":10,"studyCount":192,"speciesCounts":{"human":181,"primate":1,"pig":10},"grade":"B","forms":["gluconate","picolinate","citrate","oxide","sulfate","bisglycinate"],"evidence_grade":"A","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Zinc","papers":88,"withData":74,"pkValues":402,"species":{"human":50,"in_vitro":21,"pig":3},"pairs":{"picolinate-vs-gluconate":[null,"no direct comparison in extracted data"],"citrate-vs-oxide":[null,"no direct comparison in extracted data"]},"indirect_unavailable":[["gluconate vs picolinate","no human single-form arm with a printed value for Picolinate"],["citrate vs oxide","no matched condition set: arms differ on matrix"]],"indirect":[]},"page_url":"https://supplementabsorption.com/zinc"},{"slug":"omega-3","name":"Omega-3 / Fish Oil","rank":3,"studyCount":164,"speciesCounts":{"human":102,"primate":1,"pig":6,"rodent":23,"other_animal":24,"in_vitro":1,"unclear":7},"grade":"B","forms":["ethyl-ester","triglyceride","phospholipid","free-fatty-acid"],"evidence_grade":"A","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Omega-3 / Fish Oil","papers":78,"withData":65,"pkValues":719,"species":{"human":44,"rodent":12,"in_vitro":6,"other_animal":2,"pig":1},"pairs":{"triglyceride-vs-ethyl-ester":["B","4 human studies (3 randomized/crossover); majority: first form higher (3 agree, 1 contradict)"],"phospholipid-vs-triglyceride":["D","no human head-to-head; 1 non-human studies"]},"indirect_unavailable":[["ethyl-ester vs triglyceride","matched only within the same study"],["triglyceride vs phospholipid","no matched condition set: arms differ on units"]],"indirect":[["ethyl-ester-vs-phospholipid",null,1,null],["ethyl-ester-vs-free-fatty-acid","D",5,null],["triglyceride-vs-free-fatty-acid",null,1,null]]},"page_url":"https://supplementabsorption.com/omega-3"},{"slug":"vitamin-b12","name":"Vitamin B12","rank":7,"studyCount":134,"speciesCounts":{"human":82,"primate":1,"pig":5,"rodent":10,"other_animal":23,"in_vitro":1,"unclear":12},"grade":"B","forms":["cyanocobalamin","methylcobalamin","adenosylcobalamin","hydroxocobalamin"],"evidence_grade":"A","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Vitamin B12","papers":59,"withData":43,"pkValues":229,"species":{"human":29,"rodent":5,"other_animal":4,"in_vitro":4,"pig":1},"pairs":{"methylcobalamin-vs-cyanocobalamin":[null,"no direct comparison in extracted data"]},"indirect_unavailable":[["cyanocobalamin vs methylcobalamin","no human single-form arm with a printed value for Methylcobalamin"]],"indirect":[]},"page_url":"https://supplementabsorption.com/vitamin-b12"},{"slug":"calcium","name":"Calcium","rank":11,"studyCount":186,"speciesCounts":{"human":183,"rodent":1,"other_animal":2},"grade":"B","forms":["carbonate","citrate","citrate-malate"],"evidence_grade":"A","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Calcium","papers":97,"withData":77,"pkValues":879,"species":{"human":55,"in_vitro":19,"rodent":3},"pairs":{"citrate-vs-carbonate":["C","12 human studies (12 randomized/crossover); majority: first form higher (7 agree, 4 contradict)"]},"indirect_unavailable":[["carbonate vs citrate","matched only within the same study"]],"indirect":[]},"page_url":"https://supplementabsorption.com/calcium"},{"slug":"creatine","name":"Creatine","rank":23,"studyCount":68,"speciesCounts":{"human":35,"rodent":15,"other_animal":15,"unclear":3},"grade":"B","forms":["monohydrate","hcl","ethyl-ester"],"evidence_grade":"B","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"Creatine","papers":41,"withData":24,"pkValues":95,"species":{"human":12,"rodent":6,"in_vitro":5,"other_animal":1},"pairs":{"hcl-vs-monohydrate":[null,"no direct comparison in extracted data"]},"indirect_unavailable":[["monohydrate vs hcl","no human single-form arm with a printed value for HCl"]],"indirect":[]},"page_url":"https://supplementabsorption.com/creatine"},{"slug":"cbd","name":"CBD & CBDA (from hemp)","rank":99,"studyCount":193,"speciesCounts":{"human":75,"primate":2,"pig":4,"rodent":18,"other_animal":86,"in_vitro":3,"unclear":5},"grade":"B","forms":["isolate","oil","nanoemulsion","softgel","cbda-hemp-extract"],"evidence_grade":"B","evidence_grade_status":"draft — pending reviewer (rubric v2)","measured_pk_summary":{"name":"CBD (Cannabidiol, hemp)","papers":67,"withData":63,"pkValues":2028,"species":{"rodent":26,"human":21,"other_animal":11,"in_vitro":4,"primate":1},"pairs":{},"indirect_unavailable":[],"indirect":[["oil-vs-nanoemulsion","D",6,null],["oil-vs-softgel","D",3,null],["nanoemulsion-vs-softgel",null,1,null]]},"measured_pk_summary_cbda":{"name":"CBDA (Cannabidiolic acid, hemp)","papers":9,"withData":7,"pkValues":82,"species":{"other_animal":4,"rodent":1,"human":1,"in_vitro":1},"pairs":{},"indirect_unavailable":[],"indirect":[]},"aliases":["cbda"],"page_url":"https://supplementabsorption.com/cbd"}],"disclaimer":"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."}