Calcium bioavailability from calcium carbonate and calcium citrate.
Fourteen normal subjects took 1000 mg calcium orally as calcium citrate or calcium carbonate. The amount of calcium absorbed was estimated from the rise in urinary calcium. 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. Thus, calcium citrate provides a more optimum calcium bioavailability than calcium carbonate.
D000284:Administration, Oral; D000328:Adult; D001682:Biological Availability; D002118:Calcium / Q000097:blood*; D002119:Calcium Carbonate / Q000008:administration & dosage* / Q000378:metabolism; D002951:Citrates / Q000008:administration & dosage* / Q000378:metabolism; D019343:Citric Acid; D005260:Female; D006801:Humans; D007408:Intestinal Absorption; D008297:Male; D012995:Solubility
D002951:Citrates; D019343:Citric Acid; D002119:Calcium Carbonate; D002118:Calcium