The emerging role of vitamins as antioxidants

The recommended dietary allowances for vitamins are designed to estimate the levels of intake needed to prevent known deficiency states in most healthy people. Evidence is now accumulating that some vitamins may have health-promoting benefits in amounts higher than the current recommendations. The antioxidant properties of vitamins may play a role in treating or preventing a variety of disorders, including atherosclerosis, age-related cataracts and macular degeneration, and some cancers. This article reviews the possible risks and benefits of high intakes of antioxidant vitamins, including the controversy about supplementation.