Q: What do you think of vitamin E supplements?
A: Except for calcium and iron in women, I have long opposed the use of vitamin supplements, especially megadoses (10 to 1,000 times the Recommended Daily Allowances), in otherwise healthy individuals. Recently, however, a number of studies suggest that supplementary vitamin E may be beneficial.
A major action of vitamin E (as well as carotene and vitamins A and C) is as an antioxidant, neutralizing the effects of highly reactive free radicals constantly formed during chemical reactions in the body.
Damage to molecules and cells by free radicals has been implicated as a cause or co-factor in the development of cancer, coronary artery disease, cataracts and a number of other disorders. For example, free-radical-induced oxidation of the unsaturated fatty acids carried on low-density lipoproteins (LDL) now thought to trigger the uptake and deposition of LDL in cells of the arterial wall, the initial step in atherosclerosis. Laboratory studies indicate that the addition of vitamin E can slow LDL oxidation.
All the available information on the possible benefits of vitamin E in humans is based on epidemiological (population) studies. So far, no controlled intervention trials, during which subjects are given either vitamin E or a placebo, have been carried out to determine whether vitamin E slows the development of coronary disease or is helpful in prevention or treatment of any other disorder. The final answer on the benefits of supplemental vitamin E awaits the completion of such trials.
Vitamin E supplements (200 to 600 milligrams daily) are widely used, especially by older Americans. These amounts of vitamin E are well tolerated and have no serious side effects, except possibly in people taking anticoagulants or deficient in vitamin K.
The bottom line is that vitamin E supplements are safe and may be beneficial. I do not take vitamin E myself and have not recommended it for my family, friends or patients. If I live long
enough, maybe I will in the future.
Dr. Margolis is professor of medicine and biological chemistry at the Johns Hopkins School of Medicine and associate dean for faculty affairs at the school.