What is vitamin E?
Vitamin E is a powerful, fat-soluble antioxidant that helps protect cell membranes against damage caused by free radicals and prevents the oxidation of LDL cholesterol. The term vitamin E encompasses a group of eight compounds, called tocopherols and tocotrienols, that comprise the vitamin complex as it is found in nature.
Why is vitamin E necessary?
Vitamin E is necessary for structural and functional maintenance of skeletal, cardiac, and smooth muscle. It also assists in the formation of red blood cells and helps to maintain stores of vitamins A and K, iron, and selenium. It may have a positive effect on immune health, protect against the oxidative damage that can lead to heart disease, have preventive effects against cancer, help relieve symptoms of Alzheimer's disease, and may help prevent some diabetes-related damage, particularly to the eyes.
What are the signs of a deficiency?
Vitamin E deficiency is rare in humans. People who cannot absorb dietary fat or who have rare disorders of fat metabolism cannot absorb vitamin E. Premature or very low birth weight infants and individuals with rare genetic abnormalities in the alpha-tocopherol transfer protein may also be at risk. Symptoms include greasy stools, chronic diarrhea and an inability to secrete bile.
How much, and what kind, does an adult need?
According to the National Institutes of Health (NIH), the U.S. Recommended Daily Allowance (RDA) for adults older than 14-years is 15 mg (or 22.5 IU); pregnant women of any age should get 15 mg (or 22.5 IU); and breastfeeding women of any age should take 19 mg (or 28.5 IU).
Dr. Weil recommends supplementing with vitamin E that provides a minimum daily dose of 80 mg of the whole complex, including mixed tocopherols and mixed tocotrienols. It should provide at least 10 mg of tocotrienols. If you can't find that, look for a product with mixed natural tocopherols (400 to 800 IU daily). Avoid dl-alpha-tocopherol, the synthetic form.
How much does a child need?
The NIH's RDA and Adequate Intake (AI):
- children 1-3 years, 6 mg/day (9 IU/day)
- children 4-8 years, 7 mg/day (10.5 IU/day)
- children 9-13 years, 11 mg/day (16.5 IU/day).
How do you get enough vitamin E from foods?
Good food sources of vitamin E include vegetable oils, avocados, spinach, sunflower seeds, wheat germ, nuts, and whole grains.
Are there any risks associated with too much vitamin E?
Except for an anticoagulant effect, vitamin E has no known toxicity or side effects. Vitamin E in very high doses may interfere with the body's ability to clot blood, posing a risk to people already taking prescribed blood thinners.
Are there any other special considerations?
- Because vitamin E is fat-soluble, it's best absorbed when taken with a meal containing some fat.
- Vitamin E loses its potency when exposed to air, heat, and light, so supplements should be stored in a dark, cool place.
- People who are taking anticoagulants (blood thinners or aspirin) should take vitamin E supplements only under physician supervision.
- If you are taking statins, do not exceed 800 IU of vitamin E because it can dramatically reduce the benefits of some cholesterol drugs.
- Adverse effects may also occur when taking vitamin E and chemotherapy drugs, or mineral oil.
- Vitamin E absorption may be altered when taking the pharmaceuticals Cholestyramine, Colestipol and Orlistat.
- Levels of vitamin E may be affected by seizure medications, zinc and fish oils.
- High doses of vitamin E may increase the body's vitamin K requirement, and increased intake of omega-6 fatty acids may increase vitamin E requirements.
Updated by: Andrew Weil, M.D., and Brian Becker, M.D., on Oct. 29th, 2012
Are you getting the supplements you need?
Everyone's dietary needs are different based on a number of factors including lifestyle, diet, medications and more. To find out which supplements are right for you, take the Weil Vitamin Advisor. This 3-step questionnaire requires just minutes to complete, and generates a free, no-obligation vitamin and nutritional supplement recommendation that is personalized to meet your unique nutritional needs.