The two-fold objectives of the proposed research are 1) definition of the process of intestinal absorption of conjugated folates and 2) definition of the effect of chronic alcoholism on intestinal and hepatic folate metabolism. The method of jejunal perfusion of 3H-pteroylmonoglutamate and pteroyl 14C-glutamylhepatglutamate will be used to compare the absorption of simple and conjugated folate in alcoholic patients, in patients receiving chronic diphenylhydantoin therapy, and in patients studied before and after the jejuno-ileal bypass procedure for obesity. Jejunal mucosal folate conjugase, shown to have separate brush border and intracellular activities, will be purified, characterized, and localized by immunofluorescent techniques with the aim of showing a multistep sequence of mucosal digestion and transport of conjugated folate. Folate metabolism will be studied in monkeys pair fed ethanol as 50% of total calories. These studies will correlate progressive alcoholic liver injury with impaired synthesis of storage folate (pteroylpolyglutamate) and will measure the effect of chronic alcohol ingestion, with and without associated dietary folate deficiency, upon the intestinal absorption of simple and conjugated folate.