WASHINGTON, DC. An expert panel of the US National Academy of Sciences' Institute of Medicine has advised modest increases to the recommended daily intakes of vitamin C, vitamin E, and selenium. The new levels for vitamin C are 90 mg/day for men and 75 mg/day for women. Smokers are advised to get an additional 35 mg/day. The level for vitamin E is now set at 15 mg/day and for selenium at 55 micrograms/day. The panel also, for the first time, set "tolerable upper intake levels" for the three antioxidants. These levels represent the maximum intake that is likely to pose no health risks for most people. The upper limits are 2000 mg/day of vitamin C for both men and women, 1000 mg/day of vitamin E, and 400 micrograms/day of selenium. The panel did not recommend limits for beta-carotene and other carotenoids and cautioned that beta-carotene supplementation should only be used to prevent or correct a vitamin A deficiency. They also cautioned against extrapolating beneficial effects observed with certain foods (eg. tomatoes) to a specific component in the food (eg. lycopene) and certainly stopped a long way short of recommending megadoses of vitamins or antioxidants for the prevention or treatment of diseases like cancer and heart disease.
Reynolds, Tom. Antioxidants and cancer: what is the evidence? Journal of the National Cancer Institute, Vol. 92, July 5, 2000, pp. 1033-34