[Recommended dietary allowances of fat-soluble vitamins]

In Japan the recommended dietary allowances (RDAs) of vitamin A for adult male is calculated at 600 micrograms RE, on the data in a human vitamin A depletion-repletion study that minimum requirement for maintenance of a adequate retinol storage at liver is 6.6 micrograms/kg body weight/day. By contrast, it is estimated at 1,000 micrograms RE in U.S., on the basis of a study that minimum requirement for prevention of follicular hyperkeratosis, not impaired dark adaptation, is 910 micrograms RE/day in most adult men. On fourth edition of Japanese RDAs in 1989, the estimated safe and adequate daily dietary intake of vitamin E for adult male was established at 8 mg alpha TE, on the data that the average of unsaturated fatty acid intake was 14.3 g/day and a desirable [vitamin E (mg) to PUFA (g)] ratio of 0.4, whereas the 8-10th editions of U.S. RDAs of vitamin E for adult male had been estimated at 10 mg alpha TE. And the RDAs of other fat-soluble vitamins were discussed on the differences between Japan and other countries.