Vitamin E is another fat-soluble vitamin. Vitamin E belongs to a group of compounds called tocopherols. Alpha tocopherol is known as the most common and potent form of Vitamin E, which requires only a small amount of dietary fat in order to be absorbed by the body. Vitamin E is one of the many nutrients that have protective properties. The main function of Vitamin E is to maintain the integrity of the body’s intracellular membrane by protecting its physical stability and providing a defense line against tissue damage caused by oxidation. The body's cell membrane is made up of polyunsaturated fatty acids that are easily destroyed by oxidation. Oxidation produces free radicals that are highly reactive molecule fragments that destroy other molecules they come in contact with.

Vitamin E is known to protect cellular and subcellular membranes. For example, Vitamin E protects the cell membranes in the lungs from being damaged by exposure to high oxygen concentration and the effects of environmental pollution, which is believed to contribute in tumor growth. The red blood cells that carry oxygen from the lungs to other tissues in the body is also protected by the antioxidant effects of Vitamin E. For example, Vitamin E is also known to prevent certain types of anemia by protecting red blood cell membranes from being damaged. Aside from that, Vitamin E is also believed to protect white blood cells that boost the immune system and defend the body against diseases.

Vitamin E also protects other tissues, such as the eyes, skin, liver, breast and calf muscles; helps direct the body to properly use and store Vitamin A. Vitamin E has influential effects on other body processes too. This includes blood pressure control, normal nerve development, reproductive processes, and muscle contraction by way of interacting with certain hormone-like substances that control these processes.

Vitamin E's interrelationship with other nutrients is noteworthy. For example, as an antioxidant, Vitamin E protects fats and Vitamin A in the body from being destroyed by free radicals. In animal studies, Vitamin E interferes with the absorption of Vitamin A and K in the intestines. At the same token, Vitamin E inhibits the effects of Vitamin K's function in blood clotting. This is because Vitamin E promotes the thinning of the blood, thus minimizing blood clotting. Therefore, for heart or stroke patients and people who are taking Coumadin for the purpose of thinning their blood, they may need to avoid Vitamin E supplements to prevent the risk of excessive bleeding.

To this date, there have been many "extravagant" claims about Vitamin E’s "miraculous" power. Several decades of claims indicated that Vitamin E improves athletic performance, reduces blood sugar levels in diabetic patients, and prolongs the heart’s life by reversing the damages caused by atherosclerosis or heart attacks. Other claims also said that Vitamin E improves sexual performance, reduces pain and stiffness due to rheumatoid arthritis, and prevents premature aging. Unfortunately, these claims remain controversial. Although some studies declared their blessings to these claims, many other studies have also discredited these claims.

Henceforth, the reported correlation between Vitamin E and heart disease has been shown in some studies. Some studies indicated that Vitamin E helps prevent premature heart disease by hindering platelets that cause atherosclerosis. However, other scientists also believe that the overall role of Vitamin E in the prevention or treatment of heart disease or effects on cardiovascular incidents requires further investigation. For this reason, I would like to point out that taking mega doses of Vitamin E does not provide extra health benefits.

It is important to remember however, that Vitamin E's antioxidant function is paramount in many body processes. In addition, the rule of proper nutrition and physical activity should remain the focal point in prolonging the life of the heart and promoting good health.

Functions

As an antioxidant:

• Protects cellular and subcellular membranes in the body
• Protects fats and Vitamin A from free radicals
• May slow down premature aging by way of its protective effects from free radicals caused by environmental factors.
• May prevent cancer growth
• May lower blood sugar levels in diabetic patients
• Inhibits platelet formation that are associated with atherosclerosis

Deficiencies

There are two reasons why to this date, deficiency of Vitamin E is rare. First, Vitamin E is so widespread in most foods that you eat. Secondly, Vitamin E is abundantly stored in fatty tissues in the body. There is an exception, however, that in pregnancy it is believed that the transfer of Vitamin E from the mother to the fetus is low until the last week of pregnancy. Therefore, newborn infants may show low levels of Vitamin E which may result in certain developmental defects. Low levels of Vitamin E in infants can cause the red blood cells to rupture resulting in anemia, therefore infants are given Vitamin E supplements.

In adults, a reported condition associated with Vitamin E deficiency and caffeine toxicity is fibrocystic breast disease (lumps in the breasts) which is reported to respond to Vitamin E supplementation and abstinence from caffeine. Another reported disorder is night cramps in the calves.

People who are on extremely low fat diets in which most of their dietary fat intake are composed largely of highly processed foods may show some Vitamin E deficiencies. Highly processed foods undergo extensive heating at high temperature which is believed to destroy Vitamin E. Therefore, some food manufacturers use a fortification process whereby Vitamin E is added back into the foods.

Consequently, some diseases may cause Vitamin E deficiencies. Because Vitamin E is a fat-soluble vitamin, conditions that cause fat malabsorption may cause Vitamin E deficiency. For example, diseases of the liver, gallbladder and the pancreas where fat absorption/digestion is affected, Vitamin E absorption does not take place. Such conditions can result in neurological disorders in adults and abnormal nervous system development in infants.

Toxicity

According to several studies, cases of Vitamin E toxicity are rare. Reports of nausea and intestinal distress have only been reported in laboratory animal studies. It is important to remember however, that fat-soluble vitamins may cause toxic effects if taken in an excessive amount. Because Vitamin E is a fat-soluble vitamin, I strongly encourage you to use the RDA for this vitamin. To this date, research studies do not show that taking extra doses of Vitamin E provides extra health benefits.

The Recommended Dietary Allowance (RDA)

The Recommended Dietary Allowance (RDA) for Vitamin E is expressed in Alpha-Tocopherol Equivalents (TE).

Food Sources

-- Ofelia B. Mutia, M.S.,R.D.,L.D.

Resources and Acknowledgments

1. Understanding Normal & Clinical Nutrition by Whitney, Cataldo & Rolfes
2. The Essential Guide to Vitamins and Minerals by Elizabeth Somer, M.A.,R.D.
3. Nutrition Concepts & Controversies by Hamilton, Whitney & Sizer
4. Advanced Nutrition and Human Metabolism by James L. Groff, Sareen S. Gropper
5. Bowes & Church's Food Values of Portions Commonly Used by Jean A.T. Pennington, Ph.D., Anna De Planter Bowes, Helen N. Church
6. Essentials of Nutrition and Diet Therapy by Sue Rodwell Williams