Clinical Fact Sheet-Vitamin E and Beta-Carotene (alpha-tocopherol)

January 2001; Volume 4; S1-S2

Although vitamin e is found only in small amounts in the diet, deficiency is rare. Likewise, supplementation to prevent deficiency in adults is not warranted. Vitamin E is used most widely as a dietary supplement for the prevention of cardiovascular disease.

Dietary Reference Intakes (DRI)

4 mg/d for children 0-6 mo 7 mg/d for children 4-8 y

6 mg/d for children 7-12 mo 11 mg/d for children 9-13 y

6 mg/d for children 1-3 y 15 mg/d for men and women 14 y and older

Active Constituents

Vitamin E is a fat-soluble vitamin that consists of a family of eight compounds: four tocopherols (alpha, beta, gamma, and delta) and four additional tocotrienol derivatives. Natural vitamin E (d-alpha tocopherol) is the most bioavailable; however, claims of its superiority over synthetic vitamin E (dl-alpha tocopherol) remain controversial.

Food Sources

• Vegetable oils, wheat germ oil, seeds, nuts, soybeans, leafy greens, brussels sprouts, whole wheat products, whole grain breads and cereals, avocados, spinach, and asparagus.

Mechanism of Action

• Functions as a free radical scavenger and prevents oxidative damage to lipid membranes and LDL.

• Enhances T lymphocyte function.

Clinical Uses

• To reduce the risk of cardiovascular disease by decreasing platelet stickiness, protecting blood vessels against developing atherosclerotic lesions, and protecting LDL-cholesterol against oxidation.

• To reduce the risk of certain cancers, including lung, oral, colon, rectal, cervical, prostate, pancreatic, and liver.

• To reduce the risk and slow the progression of Alzheimer's disease and other dementias.

• To reduce the symptoms of premenstrual syndrome.

• To improve sperm function and fertility rates.

• To normalize retinal blood flow and to improve renal function in type 1 diabetics.

• To enhance immune system function and increase resistance to infection.

• To reduce the amount of exercise-induced free radical damage and the incidence of exercise-induced muscle injury.

• To reduce the risk of macular degeneration and cataracts.

• To reduce the risk of pre-eclampsia in high-risk women.

Adverse Effects/Toxicity

• The primary route of excretion of ingested vitamin E is fecal elimination.

• Vitamin E can potentiate blood clotting time; large doses are not recommended for patients taking anti-coagulant drugs (warfarin).

• Isolated cases of vitamin E toxicity have been reported in patients taking more than 1,000 IU/d. Symptoms include headache, fatigue, nausea, double vision, muscular weakness, and GI distress.

Interactions/Nutrient Depletion

• Vitamin E is destroyed by heat and oxidation during cooking or food processing.

• Absorption can be decreased by cholestyramine resin, colestipol, ethanol, isoniazid, lopid, and mineral oil.

• Low levels of selenium and high intake of polyunsaturated fatty acids contribute to vitamin E depletion.

• Co-administration with iron may delay absorption.

• Absorption depends on the presence of bile and is reduced in those people taking orlistat or with fat malabsorption syndromes (pancreatic and liver disease).