The Recommended Dietary Allowances (RDA) of vitamin E is 10 milligrams for the adult male and 8 milligrams for the adult female. Your RDA of vitamin E can be achieved without supplements by eating plant oils (vegetable oil, margarine, salad dressings), dark green and leafy vegetables, whole cereal grain products, liver, egg yolks, milk fat, nuts, seeds or butter.
Vitamin E is a fat-soluble vitamin and is stored in the body. There is, however, no known case of toxicity due to excess vitamin E.
Unfortunately, because of the role vitamin E plays in your body as an antioxidant, it has been touted as an “anti-aging” vitamin, which is not true. Vitamin E does combine with oxygen which is beneficial to polyunsaturated fats and vitamin A. Both polyunsaturated oils and vitamin A combine with oxygen and break down. Vitamin E interferes with that breakdown process. Because of its antioxidant properties, vitamin E is stable to most cooking methods except long cooking at very high temperatures that would break down fat as well.
Vitamin E deficiency has not been proven in humans, but it has in animals. Vitamin E is so widespread in foods that it is difficult to produce a deficiency in humans. Also, because it can be stored in the body, it is difficult to produce a deficiency. I suppose it would be possible to induce a vitamin E deficiency by eating an extremely low-fat diet for a prolonged period of time. Other fat soluble vitamin deficiencies would also appear though.