The bioavilability of vitamin A and E was studied in 21 healthy males aged 21-24 years by the daily oral administration of a multivitamin preparation for 44 weeks. The subjects were randomly divided into three groups in term of the daily dosage : a group receiving 4,000 IU of vitamin A and 20 mg of vitamin E acetate, a group receiving 2,000 IU of vitamin A and 10 mg of vitamin E acetate, and a placebo group. 1. With respect to plasma retinol levels, there were no significant changes and differences among the three groups throughout the study period. 2. With respect to plasma tocopherol levels, the following was noted. (a) α-Tocopherol level : There were no significant changes and differences in the levels between the placebo and 10 mg groups throughout the study period. In the 20 mg group, however, plasma α-tocopherol levels showed a significant elevation at 22, 38, and 44 weeks when compared with those in the placebo group. (b) γ-Tocopherol level : No significant differences were observed among the three groups during the study period.