Abstract
Twelve healthy male volunteers received six formulations of calcium supplements on 6 different days. During a 12-hour experimental procedure following an overnight fast, serum calcium increments were measured after ingestion of two doses of ossein-hydroxyapatite complex (HA), two different preparations of calcium gluconolactate and carbonate (sparkling tablets and powder; CSF and SC), tricalcium phosphate (PC), and calcium pidolate (CPi). Highly significant increases in serum calcium were reported following CSF and SC intake, while HA did not induce any significant variation. Calcium pidolate induced a marginal and short-term increase in serum calcium and tricalcium phosphate ingestion was followed by a slight increase of serum calcium after 720 minutes. From these data, it appears that the bioavailability of calcium supplements can vary significantly according to their type and formulation. When calcium supplements are used in the prevention and treatment of postmenopausal osteoporosis, a formulation that provides maximum bioavailability of calcium should be chosen.