A Complete Look at Vitamin E

Print This Post

Email This Post

RSS Updates

Email Updates

Vitamin E or Tocopherol, is a fat-soluble vitamin in eight forms. It is an important antioxidant often found in skin creams and lotions. It is believed to play a role in promoting skin healing and reducing scars after burns or injury.

The most active form of vitamin E in humans is Alpha-tocopherol, which is a powerful biological antioxidant. The Recommended Daly Allowance of vitamin E is based on the alpha-tocopherol form. The Institute of Medicine indicates most North American adults get enough vitamin E from their normal diets to meet the current recommendations. However, they do caution those who consume low fat diets because vegetable oils are such a good dietary source of vitamin E.

Antioxidants such as vitamin E protect cells against the effects of free radicals, which are potentially damaging by-products of the body’s metabolism. Cardiovascular disease and cancer can develop when these free radicals damage the cells. Vitamin C and other anti-oxidants recycle vitamin E end products back into effective suppressors of free radicals. There are studies being conducted to determine if vitamin E can help prevent or delay the development of those chronic diseases.

Sources of Vitamin E

The main sources of vitamin E include vegetable oils, nuts, wheat germ and green leafy vegetables. In the United States, fortified breakfast cereals are also an important source of vitamin E. Most natural vitamin E supplements are derived from vegetable oils usually soybean oil.

Deficiencies

Vitamin E deficiency is seen in people who can not absorb dietary fat and people with rare disorders of fat metabolism. Those who can not absorb fats must take a vitamin E supplement since dietary fat is needed to absorb vitamin E from the gastrointestinal tract. Individuals, who have had part or all of their stomach removed, have been diagnosed with cystic fibrosis or Crohn’s disease may not absorb fat and should discuss the need for a supplement with their physician. Those who can not absorb fat often have greasy stools or have chronic diarrhea.

Very low weight birth infants may be deficient in vitamin E. These infants are under the care of a neonatologist who evaluates and treats the exact nutritional needs of premature infants.

Abetalipoproteinemia is a rare inherited disorder of fat metabolism that results in poor absorption of dietary fat and vitamin E. The deficiency associated with this disease causes problems which include poor transmission of nerve impulses, muscle weakness, and degeneration of the retina that can cause blindness. Individuals diagnosed with this condition are given special supplements by a physician.

Current Issues and Controversies

Some research has indicated vitamin e can prevent or delay heart disease. Researchers have indicated that oxidative modification of LDL-cholesterol promotes blockages in coronary arteries which can lead to atherosclerosis and heart attacks. Vitamin E may help prevent or delay coronary heart disease by limiting the oxidation of the LDL cholesterol. It can also help prevent the formation of blood clots, which can cause heart attacks. Studies have shown lower rates of heart disease with higher vitamin E intake.

A study done of 90,000 nurses suggest heart disease was 30%-40% lower among nurses with the highest intake of vitamin E from diet and supplements. The range of intakes in this group were 21.6 to 1,000 IU (32-1500 mg) with the medium intake being 208 IU (139 mg) However, The Heart Outcomes Prevention Evaluation (HOPE) Study followed 10,000 patients for 4.5 years who were at higher risk for heart attack and stroke. In this intervention study the subjects received 400 IU (265 mg) of vitamin E daily. They did not experience significantly lower cardiovascular events when compared to those who received a sugar pill. The researchers concluded that vitamin E supplement did not provide any protection against cardiovascular disease. The study is continuing however to determine if a longer duration has any affect.

It is indicated that antioxidants such as vitamin E help protect against the developments of chronic diseases such as cancer. Vitamin E may also block the formation of nitrosamines, which are carcinogens formed in the stomach from nitrates consumed in the diet. It may also enhance immune function which may prevent against the development of cancers. There is however no conclusive studies done which prove this.

Some evidence does suggest higher vitamin E intakes decrease incidence of prostate cancer and breast cancer. A study done of women in Iowa provided evidence that increased vitamin E may decrease the risk of colon cancer, especially in women under age 65. However, vitamin E intake was not statistically associated with risk of colon cancer in almost 2,000 adults with cancer compared to controls without cancer. At this time there is limited evidence suggested vitamin E supplements should be used to prevent cancer.

Antioxidants are being studied to see if they can help prevent or delay cataract growth in the eye. Observational studies indicate lens clarity was better in regular vitamin E users. A study of middle age male smokers did not demonstrate any effect from vitamin E supplements. The effects of smoking may have overridden any benefit from the vitamin E.

An observational study done by the Johns Hopkins University Bloomberg School of Public Health found that when large doses of vitamin E is taken (400-1000IU) in combination with vitamin C (500-1000mg) the onset of Alzheimer’s was reduced between 64 -78%.

A study was done in 2005, published in The Lancet Neurology, suggesting vitamin E may help prevent Parkinson’s disease. Those with moderate to high intakes of dietary vitamin E were found to have a lower risk of this disease.

Excess Consumption Risks

The health risks of too much vitamin E are disputed. In the elderly, a recent study indicated taking doses of 530 mg or 800 IU (35 times the current RDA) for up to four months had no significant effect on general health. The long term effects of such dosage however, have not been tested. The Institute of Medicine has set an upper intake level of vitamin E of 1,000 mg (1,500 IU) per day since the nutrient can also act as an anticoagulant and increase the risk of bleeding problems.

Popularity: 17% [?]