Vitamin deficiencies are often induced by alcohol intake presumably due to disturbance of utilization and increased requirements of vitamins. In this study, disturbances of B_1 utilization and changes in the B_1 requirement were evaluated in humans by B_1 tolerance test and alcohol tolerance test. Utilization of B_1 was reduced in patients with liver disorders, and alcohol was suspected to increase the B_1 requirement even in those without liver disorders. Alcohol is often a factor in beriberi and Wernicke's encephalopathy. It is also known to be involved in pellagra, of which only 8 cases were presented since pellagra is uncommon in Japan. Moreover, anemia was observed in 34.9% of alcohol-dependent individuals, and folic acid deficiency was suspected to be a cause of macrocytic anemia. A lipid tolerance test using retinyl palmitate (A-pal) showed reduced ability of A-pal metabolism in patients with hyperlipidemia (type IV) after alcohol administration. These results suggest that the ability of chylomicron deposition is reduced, and drinking increases the risk of hypervitaminosis A in hyperlipidemic patients.