This fat-soluble vitamin discovered at UC Berkeley more than 80 years ago has been a star among nutrients for at least 25 years. Vitamin E is an important antioxidant that exists in several forms, the most potent of which is alpha tocopherol, the form usually found in Vitamin E supplements. Like other antioxidants, Vitamin E protects cells against the effects of free radicals, which are potentially damaging by-products of life processes. Free radicals can damage cells and may contribute to the development of heart disease and cancer. Vitamin E may play a role in immune function. The RDA for vitamin E is just 15 milligrams (about 23 IU) a day. The upper limit is 1,000 milligrams (about 1,500 IU) a day.

In 1994, reacting to promising research, the Wellness Letter began recommending vitamin E supplements as a possible way to reduce the risk of heart disease, cancer, and other disorders. After reviewing subsequent clinical trials that had yielded disappointing or conflicting results, we softened our endorsement of vitamin E supplements. In 2004 a much-publicized meta-analysis from Johns Hopkins Medical Institutions concluded that high doses of vitamin E (more than 400 IU a day) taken long term may slightly increase the overall risk of dying—by about 4%. Lower doses of vitamin E (200 IU or less) did not increase the risk. Three other meta-analyses on vitamin E found no increased risk.

Claims, purported benefits: Helps prevent cancer, heart disease, cataracts; boosts immunity.

Bottom line: While vitamin E from foods is important for health, there’s little or no clinical research showing that vitamin E supplements are beneficial. Nearly all the clinical trials on vitamin E from the past few years have yielded negative, inconclusive, or neutral results. Get vitamin E from foods—nuts, seeds, vegetable oils, whole grains, and leafy greens. There is no reason to take vitamin E supplements.