Vitamin E is a fat-soluble nutrient found in many foods. In the body, it acts as an antioxidant, helping to protect cells from the damage caused by free radicals. Free radicals are compounds formed when our bodies convert the food we eat into energy. People are also exposed to free radicals in the environment from cigarette smoke, air pollution, and ultraviolet light from the sun.
The body also needs vitamin E to boost its immune system so that it can fight off invading bacteria and viruses. It helps to widen blood vessels and keep blood from clotting within them. In addition, cells use vitamin E to interact with each other and to carry out many important functions.
The amount of vitamin E you need each day depends on your age. Average daily recommended intakes are listed below in milligrams (mg) and in International Units (IU). Package labels list the amount of vitamin E in foods and dietary supplements in IU.
|Life Stage||Recommended Amount|
|Birth to 6 months||4 mg (6 IU)|
|Infants 7-12 months||5 mg (7.5 IU)|
|Children 1-3 years||6 mg (9 IU)|
|Children 4-8 years||7 mg (10.4 IU)|
|Children 9-13 years||11 mg (16.4 IU)|
|Teens 14-18 years||15 mg (22.4 IU)|
|Adults||15 mg (22.4 IU)|
|Pregnant teens and women||15 mg (22.4 IU)|
|Breastfeeding teens and women||19 mg (28.4 IU)|
Most once-daily multivitamin-mineral supplements provide about 30 IU of vitamin E, whereas vitamin E-only supplements usually contain 100 to 1,000 IU per pill. The doses in vitamin E-only supplements are much higher than the recommended amounts. Some people take large doses because they believe or hope that doing so will keep them healthy or lower their risk of certain diseases.
Although vitamin E sounds like a single substance, it is actually the name of eight related compounds in food, including alpha-tocopherol. Each form has a different potency, or level of activity in the body.
Vitamin E from natural (food) sources is commonly listed as "d-alpha-tocopherol" on food packaging and supplement labels. Synthetic (laboratory-made) vitamin E is commonly listed as "dl-alpha-tocopherol." The natural form is more potent. For example, 100 IU of natural vitamin E is equal to about 150 IU of the synthetic form.
Some vitamin E supplements provide other forms of the vitamin, such as gamma-tocopherol, tocotrienols, and mixed tocopherols. Scientists do not know if any of these forms are superior to alpha-tocopherol in supplements.
Vitamin E deficiency is very rare in healthy people. It is almost always linked to certain diseases in which fat is not properly digested or absorbed. Examples include Crohn's disease, cystic fibrosis, and certain rare genetic diseases such as abetalipoproteinemia and ataxia with vitamin E deficiency (AVED). Vitamin E needs some fat for the digestive system to absorb it.
Vitamin E deficiency can cause nerve and muscle damage that results in loss of feeling in the arms and legs, loss of body movement control, muscle weakness, and vision problems. Another sign of deficiency is a weakened immune system.
Scientists are studying vitamin E to understand how it affects health. Here are several examples of what this research has shown.
Some studies link higher intakes of vitamin E from supplements to lower chances of developing heart disease. But the best research finds no benefit. People in these studies are randomly assigned to take vitamin E or a placebo (dummy pill with no vitamin E or active ingredients) and they don't know which they are taking.
Vitamin E supplements do not seem to prevent heart disease, reduce its severity, or affect the risk of death from this disease. Scientists do not know whether high intakes of vitamin E might protect the heart in younger, healthier people who do not have a high risk of heart disease.
Most research indicates that vitamin E does not help prevent cancer and may be harmful in some cases. Large doses of vitamin E have not consistently reduced the risk of colon and breast cancer in studies, for example. A large study found that taking vitamin E supplements (400 IU/day) for several years increased the risk of developing prostate cancer in men.
Two studies that followed middle-aged men and women for 7 or more years found that extra vitamin E (300-400 IU/day, on average) did not protect them from any form of cancer. However, one study found a link between the use of vitamin E supplements for 10 years or more and a lower risk of death from bladder cancer.
Vitamin E dietary supplements and other antioxidants might interact with chemotherapy and radiation therapy. People undergoing these treatments should talk with their doctor or oncologist before taking vitamin E or other antioxidant supplements, especially in high doses.
Age-related macular degeneration (AMD), or the loss of central vision in older people, and cataracts are among the most common causes of vision loss in older people. The results of research on whether vitamin E can help prevent these conditions are inconsistent.
Among people with AMD who were at high risk of developing advanced AMD, a supplement containing large doses of vitamin E combined with other antioxidants, zinc, and copper showed promise for slowing down the rate of vision loss.
Several studies have investigated whether vitamin E supplements might help older adults remain mentally alert and active as well as prevent or slow the decline of mental function and Alzheimer's disease. So far, the research provides little evidence that taking vitamin E supplements can help healthy people or people with mild mental functioning problems to maintain brain health.
Eating vitamin E in foods is not risky or harmful.
In supplement form, however, high doses of vitamin E might increase the risk of bleeding (by reducing the blood's ability to form clots after a cut or injury) and of serious bleeding in the brain (known as hemorrhagic stroke). Because of this risk, the upper limit for adults is 1,500 IU/day for supplements made from the natural form of vitamin E and 1,100 IU/day for supplements made from synthetic vitamin E.
The upper limits for children are lower than those for adults. Some research suggests that taking vitamin E supplements even below these upper limits might cause harm. In one study, for example, men who took 400 IU of vitamin E each day for several years had an increased risk of prostate cancer.
Vitamin E dietary supplements can interact or interfere with certain medicines that you take. Here are some examples:
Tell your doctor, pharmacist, and other healthcare providers about any dietary supplements and medicines you take. They can tell you if those dietary supplements might interact or interfere with your prescription or over-the-counter medicines, or if the medicines might interfere with how your body absorbs, uses, or breaks down nutrients.
People should get most of their nutrients from food. Foods contain vitamins, minerals, dietary fiber and other substances that benefit health. In some cases, fortified foods and dietary supplements may provide nutrients that otherwise may be consumed in less-than-recommended amounts.