Effect of Cholestyramine, a Bile Acid Binding Polymer, on Vitamin K1 Absorption in Dogs

Summary Studies were undertaken to determine whether or not cholestyramine, a bile acid binding resin, would interfere with the intestinal absorption of fat-soluble vitamins. The studies were designed to give the resin an optimal opportunity to interfere with Vit. K1 absorption. Administration of cholestyramine in a dose range recommended for human use had no effect on Vit. K1 absorption. Large doses of the resin, administered before and shortly after feeding the vitamin, did delay and decrease the absorption of this vitamin. However, very large doses of cholestyramine given 17 hours before feeding Vit. K1 had no affect on the availability of the vitamin. These studies suggest that cholestyramine would not be expected to interfere with the absorption of Vit. K when the resin is used under practical clinical conditions in man. However, the resin may be a useful experimental tool to investigate the role of bile acids in fat absorption.