Contribution of biliary lipids to calcium binding in bile.

As part of a detailed study into the solubility of calcium in bile, the contribution of the biliary lipids, bile salt, lecithin, and cholesterole to calcium binding in bile has been assessed. Micellar binding could account for 80% of the calcium binding in hepatic bile but only 50% in gallbladder bile. It is suggested that such binding, in soluble form, lowers the activity of calcium in bile, and therefore its liability to precipitation as gallstone nuclei.