The Absorption of Calcium Carbonate

Abstract

The absorption of calcium carbonate (CaCO3) was evaluated in normal subjects, patients with peptic ulcer disease and patients with past evidence of the milk alkali syndrome. When a single dose of 1 to 12 g CaCO3 was given to normal fasting subjects, a transient rise of the concentration of Ca in blood, often to low hypercalcemlc values, was observed. Other patients were given 2 g CaCO3 labeled with Ca45 to allow direct measurement of the per cent of the dose which was absorbed. Five subjects with normal Ca metabolism and gastrointestinal function and 5 patients with clinical diagnosis of subacute milk alkali syndrome absorbed CaCO3 equally well; the average absorption for the group being 16. 6 [plus or minus] 8. 5 percent. This was only slightly less than the percentage absorption of a comparable dose of Ca given in the form of calcium gluconate. The only subjects who failed to absorb CaCO3 were patients who were found not to secrete free acid in their gastric juices.