Intake Increased the GallStone Formation in Guinea Pigs Due to High Oral Calcium Intake

ABSTRACT

Oral calcium supplementation has been recommended for prevention of osteoporosis in postmenopausal women. However experimental studies have suggested that oral calcium supplementation may increase the biliary calcium concentration and the incidence of gallstone formation in some animals. We designed an experiment to establish the effect of oral calcium supplementation in Guinea pigs. Nineteen Guinea pigs were divided into 2 groups. Group I (n=10) was fed with normal water, and group II (n=9) was fed with calcium-containing water(oscal 1000 mg/250 ml normal water). After 6 weeks, all animal were sacrifised, and the presence of gallstones was examined by inspection. Gallbladder bile and blood also were sampled. Gallstones were not found in group I, but in group II, gallstones were observed in five animals (56%). The level of calcium, bile acid, phospholipid, cholesterol, and bilirubin in the gallbladder bile was the same for both group I and group II. The levels of calcium and cholesterol in the serum was also the same for these two groups, but the level of bilirubin was remarkably lower group II than in group I. Oral calcium supplementation increased gallstone formation in guinea pigs, but there was no difference in the level of calcium in the bile composition. This present study could not confirm that oral calcium supplementation increased biliary calcium and then the incidence of gallstone formation in Guinea pigs. We think that the increase of biliary calcium after oral calcium supplementation is not the sole fator in gallstone formation and that other factors may be involved.