Vitamin E is a fat-soluble vitamin, meaning that it dissolves in fat rather than in water. By attaching to fat, Vitamin E is carried through the body. This is one reason why moderate amounts of fat are needed in the diet. The body can store fat-soluble vitamins. However, because the body does not excrete vitamin E as it would a water-soluble vitamin, it is possible to accumulate vitamin E to toxic levels if too much is taken in.
What food source is the nutrient found in?
Vitamin E is found in the fatty parts of foods. The best sources of vitamin E are unsaturated fats, such as vegetable oils. These include sunflower, safflower, canola, olive, and wheat germ oils. It is also found in avocados, nuts, seeds, wheat germ, and whole grain, or unrefined, products. Green leafy vegetables have smaller amounts.
Soybean oil has a form of vitamin E that has little influence on health. This oil is not a good source of vitamin E. Soybean oil is the most common oil used in products like salad dressing and mayonnaise. Heating oils to high temperatures, such as in frying, can destroy vitamin E, as can storing or freezing foods for a long time.
Vitamin E is found in the germ of a seed or grain. Most of the nutrients are concentrated there. Whole-wheat flour contains much of the original germ, so it has vitamin E. Refined (white) flour has been stripped of many of its nutrients, including vitamin E.
How does the nutrient affect the body?
Vitamin E is an important antioxidant. Antioxidants protect cells from oxidation, which.can lead to cell damage, and in turn to chronic health problems, such as heart disease and cancer. Vitamin E works closely with other antioxidants, like vitamin C and selenium, to help protect the body. Vitamin E improves the way the body uses vitamin A. It may help protect against the toxic effects of some metals, such as lead.
The recommended dietary allowance (RDA) for vitamin E is currently 15 mg daily for adult men and women, 19 mg for a breastfeeding woman. It is difficult to get enough vitamin E from food alone. The government estimates that 68 percent of men and 71 percent of women do not get enough vitamin E daily. To get the full benefit of vitamin E, a supplement is recommended.
An upper level, based only on intake from vitamin supplements, has been set at 1,000 mg of alpha-tocopherol (the most potent form of vitamin E). The upper level is not the recommended amount to take; rather, it is the maximum intake of a vitamin or mineral that is likely to cause no health risks. People should not routinely go above the set upper levels for vitamins and minerals.
Taking too much vitamin E puts people at risk for prolonged bleeding time. This is because large doses can interfere with vitamin K, which helps the blood to clot when a person is bleeding.
Not enough is known about vitamin E to make positive claims as to whether larger than recommended doses of vitamin E help prevent cancer or heart disease. The results of studies have not been consistent, and research is continuing.
Severe vitamin E deficiency is rare. Conditions where it may occur include people who do not absorb fat normally, premature infants, people with red blood cell disorders, and people on kidney dialysis. Symptoms of vitamin E deficiency include nerve damage and anemia in infants. To maximize vitamin E intake, healthy vegetable oils, nuts, seeds, and unrefined whole-grain products should be a regular part of the diet.
Somer, E., MA, RD.&Health Media of America. (1995). The Essential Guide To Vitamins and Minerals (2nd ed.). New York: HarperCollins Publishers, Inc.
Duyff, R., MS, RD, CFCS. (1996). The American Dietetic Association's Complete Food&Nutrition Guide. Minnesota: Chronimed Publishing.
Murray, M., ND. (1996). Encyclopedia of Nutritional Supplements. California: Prima Publishing.
Food and Nutrition Board of the National Academy of Sciences'. (April 10, 2000). Press Release, "Antioxidants' Role in Chronic Disease Prevention Still Uncertain; Huge Doses Considered Risky"
Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium and Carotenoids, 2000, National Academy Press.
Escott-Stump, S. (1997), Nutrition and Diagnosis-related Care, Fourth Ed., Williams and Wilkins.
Anderson, J., MS, Deskins, B., PhD, RD, (1995), The Nutrition Bible, William Morrow and Co., Inc.