While vitamin E, also known as alpha tocopherol, occurs naturally in some foods, it is also added to others, and can be purchased as either natural (d-alpha tocopherol) or synthetic vitamin E (the synthetic version adds the prefix dl, rather than just d). The U.S. Department of Agriculture, or USDA, which establishes minimum daily requirements for vitamins and minerals, recommends only natural alpha tocopherol, or vitamin E.
The daily adult requirement of vitamin E, 15 milligrams (mg) per day, can come from foods like wheat germ oil, sunflower seeds, almonds, spinach, beet greens and peanut butter or peanut oil. However, individuals are more likely to reach this goal by consuming vitamin E enriched foods or supplements.
Fortunately, true vitamin E deficiencies are rare, and usually associated with genetic disorders like ataxia. In spite of that, many researchers and health professionals also consider vitamin E valuable in preventing or delaying coronary heart disease, and in preventing some cancers. An Iowa study has already shown vitamin E beneficial in reducing colon cancer among women. Another has demonstrated a lower risk of bladder cancer. There is, however, no link between vitamin E supplements (or fats in general) and an increased risk of breast cancer.
On the other hand, consumption of high levels of vitamin E foods may prevent age-related macular degeneration and cataracts. Vitamin E, in its role as an antioxidant, may also prevent age-related cognitive decline and neurological diseases like Alzheimer’s. Vitamin E is also well known among doctors for its work in supporting the immune system.
The daily adult recommended dose of vitamin E is 15 mg, or 1,500 IU (in its natural form; 1,100 IU in synthetic form). From ages 9-13, the recommendation for vitamin E is 11 mg, or 900 IU. Those over 14 need the full adult dose of vitamin E to remain healthy.
Beyond this, and over the long term, vitamin E supplements may cause: excessive bleeding, especially in the form of hemorrhagic stroke, or bleeding into the brain; an increased risk of certain cancers; an eye condition, retinitis pigmentosa; and heart failure among diabetes victims. Vitamin E may also interfere with certain prescription medications like the blood-thinner warfarin, the cholesterol-lowering simvastatin, and some chemotherapy medications.