Vitamin E is a nutrient that's important to vision, reproduction, and the health of your blood, brain and skin.
Vitamin E also has antioxidant properties. Antioxidants are substances that might protect your cells against the effects of free radicals — molecules produced when your body breaks down food or is exposed to tobacco smoke and radiation. Free radicals might play a role in heart disease, cancer and other diseases. If you take vitamin E for its antioxidant properties, keep in mind that the supplement might not offer the same benefits as naturally occurring antioxidants in food.
Foods rich in vitamin E include canola oil, olive oil, margarine, almonds and peanuts. You can also get vitamin E from meats, dairy, leafy greens and fortified cereals. Vitamin E is also available as an oral supplement in capsules or drops.
Vitamin E deficiency can cause nerve pain (neuropathy).
The recommended daily amount of vitamin E for adults is 15 milligrams a day.
Research on vitamin E use for specific conditions shows:
- Alzheimer's disease. Some research has shown that high-dose vitamin E might delay the progression of Alzheimer's disease in people who have been diagnosed with mild to moderate Alzheimer's disease. Other studies haven't shown this benefit. Vitamin E supplements appear to have no effect on whether people with mild cognitive impairment progress to Alzheimer's disease.
- Liver disease. Studies show that vitamin E might improve symptoms of nonalcoholic fatty liver disease. However, some evidence suggests that taking oral vitamin E for this purpose for two years is linked to insulin resistance.
- Preeclampsia. Increasing your intake of vitamin E hasn't been shown to prevent this pregnancy condition that affects blood pressure.
- Prostate cancer. Research shows that vitamin E and selenium supplements don't prevent prostate cancer. There is also concern that use of vitamin E supplements might increase the risk of prostate cancer.
Most people get enough vitamin E from a balanced diet. If you've been diagnosed with mild to moderate Alzheimer's disease, some research suggests that vitamin E therapy might help slow disease progression.
However, oral use of vitamin E might increase the risk of prostate cancer. Use of the supplement can pose other serious risks, particularly at high doses and if you have other health conditions or have had a heart attack or stroke.
Safety and side effects
When taken at appropriate doses, oral use of vitamin E is generally considered safe. Rarely, oral use of vitamin E can cause:
- Intestinal cramps
- Blurred vision
- Gonadal dysfunction
- Increased concentration of creatine in the urine (creatinuria)
Taking higher doses of vitamin E might increase the risk of side effects. Also, there is concern that people in poor health who take high doses of vitamin E are at increased risk of death.
Use of vitamin E can interact with many conditions. For example, research suggests that oral use of vitamin E might increase the risk of prostate cancer. Other research suggests that vitamin E use might increase the risk of death in people with a severe history of heart disease, such as heart attack or stroke. Talk with your doctor before taking vitamin E if you have:
- A vitamin K deficiency
- An eye condition in which the retina is damaged (retinitis pigmentosa)
- Bleeding disorders
- A history of a previous heart attack or stroke
- Head and neck cancer
- Liver disease
The supplement might increase your risk of bleeding. If you're planning to have surgery, stop taking vitamin E two weeks beforehand. Also, talk to your doctor about vitamin E use if you're about to have or you just had a procedure to open blocked arteries and restore normal blood flow to your heart muscle (angioplasty).
Use of some drugs can affect your vitamin E levels. Possible interactions include:
- Alkylating agents and anti-tumor antibiotics. There's concern that high doses of vitamin E might affect the use of these chemotherapy drugs.
- Anticoagulants and anti-platelet drugs, herbs and supplements. Use of vitamin E with these drugs, herbs and supplements to reduce blood clotting might increase the risk of bleeding.
- Cytochrome P450 3A4 (CYP3A4) substrates. Use caution when taking vitamin E and other drugs affected by these enzymes, such as omeprazole (Prilosec, Zegerid).
- Statins and niacin. Taking vitamin E with statins or niacin, which might benefit people with high cholesterol, could reduce niacin's effect.
- Vitamin K. Taking vitamin E with vitamin K might decrease the effects of vitamin K.