Vitamin E is a fat-soluble vitamin. Fat-soluble vitamins are stored in the liver and fatty tissues. There are 8 different forms of vitamin E—each has its own biologic activity. Alpha-tocopherol is the most active form of vitamin E in humans. It is an antioxidant—a substance that acts to protect the body's cells against the effects of free radicals. Free radicals are normal by-products of metabolism, but they can cause cell damage.
Vitamin E's functions include:
- Acting as an antioxidant in the body
- Helping with immune system function
Vitamin E Deficiency
Vitamin E deficiency is rare. In developed countries, vitamin E deficiency is seen only in certain conditions, such as liver disease or cystic fibrosis.
Symptoms of vitamin E deficiency include:
- Neurological symptoms, such as impaired balance and coordination
- Muscle weakness
- Retinal degeneration (thinning of the lining of the inner eye)
People with vitamin E deficiency may also be deficient in vitamins A, D, and K.
Vitamin E Toxicity
As a fat-soluble vitamin, vitamin E is stored in the body and is not excreted in the urine like most water-soluble vitamins. Therefore, it is possible for vitamin E to accumulate in the body. The tolerable upper intake level (UL) for adults of vitamin E from dietary sources and supplements combined is 1,000 milligrams daily. For children the UL is lower.
Major Food Sources
Populations at Risk for Vitamin E Deficiency
The following populations may be at risk for vitamin E deficiency and may require a supplement:
- People with a reduced ability to absorb dietary fat—Because vitamin E is a fat-soluble vitamin, fat is required for its absorption. Some conditions that can cause fat malabsorption include Crohn's disease, cystic fibrosis, celiac disease, pancreatic enzyme deficiency, and liver disease.
- People who have gastric bypass surgery.
- Very low birth weight infants—These infants are usually under the care of a neonatologist, who will evaluate and treat the premature infant's exact nutrition needs.
- People who suffer from abetalipoproteinemia—This is a rare inherited disorder of fat metabolism that results in poor absorption of dietary fat and vitamin E.
Free radicals are normal by-products of metabolism, but they can cause chain reactions that result in significant cell destruction. This cell destruction can, in turn, increase the risk for chronic diseases, including certain forms of cancer. Antioxidants have the ability to stop this chain reaction. Vitamin E functions in the body as an antioxidant. Because of this antioxidant capability, vitamin E is being studied for a possible role in chronic disease prevention. However, so far there is not good evidence that vitamin E helps in preventing cancer or heart disease. And in some studies, high doses of supplements actually increased the risk of death.
Tips for Increasing Your Vitamin E Intake:
To help increase your intake of vitamin E:
- Sprinkle wheat germ on your cereal or oatmeal.
- Add sunflower seeds or nuts to a salad or stir-fry.
- Add mango or blueberries to yogurt for an afternoon snack.
- If you take a vitamin supplement, make sure it contains vitamin E.
- Reviewer: Michael Woods, MD
- Review Date: 02/2015 -
- Update Date: 02/11/2015 -