Abstract
Intestinal calcium absorption from two different therapeutic preparations was compared intraindividually in 12 postmenopausal women. An amount of 800 mg of calcium as lactogluconate/carbonate or citrate was given in random order respectively. Each test dose was labelled with stable 44Ca. At the same time a tracer dose of 42Ca was injected intravenously. The amount of calcium absorbed was derived from the ratio of the stable tracers in blood serum and urine 24 hours after administration. Mean bioavailability of the calcium citrate preparation was higher (30%) than from the calcium lactogluconate/carbonate preparation (25%).