- Vitamin E exists naturally in eight forms (four tocopherols and four tocotrienols). The tocopherols are best known and have received much more research attention than the tocotrienols. Alpha tocopherol is the main type of vitamin E in the body and is probably the most important and the most often studied. Gamma tocopherol is the main form in food.
- It acts as an antioxidant—that is, it helps neutralize free radicals (oxygen molecules that can harm cells and may contribute to chronic diseases). It may work synergistically with vitamin C in reducing oxidative stress.
- It is fat-soluble and can thus be stored in the body.
- It is measured in milligrams or International Units (IU); the latter are used on supplement labels. The daily Recommended Dietary Allowance (RDA) for adults is 15 milligrams (about 23 IU). the upper limit is 1,000 milligrams (about 1,500 IU).
- Deficiency in vitamin E is unknown, except in people with rare genetic disorders or malnutrition, or in preterm infants.
Published April 19, 2013