Vitamin E Introduction

Vitamin E is the most controversial vitamin listed in the category of the fat soluble nutrients. This is due to the relative unknown effects associated with Vitamin E. The past decade has led to debates of this vitamin as a “cure-all” supplement. It has been claimed to prevent cancer, slow down aging, prevent heart attacks, and to cure many other chronic illnesses. [2] The fact remains that nutritional scientists have yet to discover the full benefits and many uses associated with Vitamin E.

What science has proven, is that Vitamin E is a well digested, potent antioxidant (a substance that prevents or delays oxidation). It exists in a group of fat soluble compounds called tocopherols, consisting in eight different forms in all. [2] The most abundant or biologically available form for human consumption is Alpha-tocopherol. This form is stored primarily in the adipose, muscle, and liver tissues.

Various sources of food must be consumed for achieving adequate intakes of Vitamin E. It is also important to note that for optimum health, the sources listed below must be minimally consumed as they exist as dietary fats.

Clinical Nutrition Service, Warren Grant Magnuson Clinical Center, National Institutes of Health (NIH), Bethesda, MD, in conjunction with the Office of Dietary Supplements (ODS) in the Office of the Director of NIH. [3]

As previously stated, Vitamin E functions primarily as an antioxidant, combating free radicals in our environment. It does this by maintaining cell membrane integrity, expelling and preventing oxidation. During periods of intense exercise and training Vitamin E may also support overall cardiovascular health while functioning as a buffer against free radicals produced from the breaking down of muscle tissue. This important vitamin has also been deemed an important component in the formation and synthesis of red blood cells.

Vitamin E has been used in clinical studies to combat the effects of cell damage caused by aging; also being employed as a preventative supplement to combat Alzheimer's disease. [4] Older Americans may also benefit from its anti-oxidative properties, ability to lower blood pressure, and decreases in Low Density Lipoproteins (bad cholesterol). [5, 6] Vitamin E may provide a adjunct treatment for the management of atherosclerosis and arthritis in older populations as well. [7]

Technological advances in modern society has led to increases in the number and use of cell-phones, TVs, computers, and other media; all of which increase our susceptibility to free radical damage. Vitamin E plays an intricate role, protecting against the effects of carcinogens, suppressing tumor growth, and reducing the toxicity of several anticancer therapies. [8] In fact, high levels of alpha-tocopherol were found to reduce risk of certain stomach cancers; however, researchers also found an increased risk of another cancer when there were high levels of alpha-tocopherol. [9]

Adult-onset diabetes is a serious and chronic illness that is steadily growing in number, as adequate dietary factors continue to diminish in Western diets. Vitamin E has been researched in various studies to analyze its affect upon the many complications associated with this condition. Initial results indicate that vitamin E may lessen the risk factors, and provide relief in persons already suffering from this condition. [10, 11]

Furthermore, women derive the greatest benefit from the dietary inclusion of Vitamin E, as it has been shown to ease the longevity and symptoms associated with pre-menstrual syndrome. Not only does Vitamin E combat the effects of PMS, but it has also been shown to reduce the risk of rectal cancer in women. [12]

1 microgram alpha-tocopherol = 1.5IUs of Vitamin E

[3]

Men intakes of Vitamin E must be considerably higher due to the differences in weight bearing characteristics.

Vitamin E Toxicities

There are very few studies that can define the topic of Vitamin E toxicity. This being said, it does exist, though it is a very rare occurrence. A recent review of the safety of Vitamin E in the elderly indicated that taking vitamin E supplements for up to four months at doses of 800 IU (35 times the current RDA) per day, had no significant effect on general health, body weight, levels of body proteins, lipid levels, liver or kidney function, thyroid hormones, amount or kinds of blood cells, and bleeding time. [13]

Many scientists speculate that excess intake of this Vitamin may result in the body’s ability to coagulate blood (excessive bleeding). It may also interfere with the metabolism of the fat-soluble Vitamin A, and a severe decrease in sexual function.

Vitamin E Deficiencies

A deficiency state of Vitamin E has not been known to exist in humans. However, this does not mean that deficiencies cannot occur. Vitamin E deficiencies may manifest in infants who suffer from Low-Birth-Weight (LBW), or those who cannot absorb dietary fats. It has also been theorized that a deficiency may impair the neurological activity of the brain. More research is necessary to accurately assess the risks and symptoms of vitamin E deficiency.

1. Institute of Medicine, Food and Nutrition board. Dietary ReferenceIntakes: Vitamin C, Vitamin E, Selenium, and Caratenoids. NationalAcademy Press, Washington, DC, 2000.

2. Herbert, Victor. “Vitamins and Minerals Plus Antioxidant Supplements” Total Nutrition Ed. Victor Herbert, M.D., Genell J.Subak-Sharpe, M.S. New York: Saint Martin’s Griffin, 1995. 94-118.

3. Clinical Nutrition Service, Warren Grant Magnuson ClinicalCenter,National Institutes of Health (NIH), NIH. Vitamin D December. 9. 2002.http://www.cc.nih.gov/ccc/supplements/

4. Lores Arnaiz S, et al. Chemiluminescence and Antioxidant LevelsDuring Perioxisome Proliferation by Finofibrate. Biochim Biophys Acta.May 1997;1360(30):222-28.

5.Jessup JV, Horne C, Yarandi H, Quindry J. The effects ofenduranceexercise and vitamin E on oxidative stress in theelderly. Biol ResNurs. July 2003;5(1-2):10-3.

6. Rezaian GR, Taheri M, Mozaffari Be, Moslegh AA, GhalamborMA.The salutary effects of antioxidant vitamins on the plasma lipids ofhealthy middle aged-to-elderly individuals: arandomized, double-blind,placebo-controlled study. J Med Liban. January 2002;50(1-2):10-3.

7. Chan AC. Vitamin E and Atherosclerosis. J Nutrition October1998;128(10):1593-96. View Abstract.

8. Das S. Vitamin E in the Genesis and Prevention of Cancer. AReview. Acta Oncol. 1994;33(6):615-19.

9. Taylor PR, Qiao YL, Abnet CC, et al. Prospective study of serum VitaminE levels and esophageal and gastric cancers. J National CancerInstitute. September 2003;95(18):1414-6.

10. Manzella D, Barbieri M, Ragno E, Paolisso G. Chronic administration ofpharmalogical doses of Vitamin E improves the cardiac autonomic nervous system in patients with type 2 diabetes. American Journal ofClinical Nutrition. June 2001;73(6):1057-7.

11. Jialal I, Devaraj S, Venugopal SK. Oxidative stress, inflammation, anddiabetic vasculopathies: the role of alpha-tocopherol therapy. FreeRadic Res. December 2002;36(12):1331-6.

12. Murtaugh MA. Antioxidants, carotenoids, and risk of rectal cancer.merican Journal Epidemiol. 2004. Jan 1: 159(1):32-41

13. Meydani SN, Meydani M, Blumberg JB, Leka LS, Pedrosa M,Diamond R, Schaefer EJ. Assessment of the safety ofsupplementation with different amounts of vitamin E in healthy olderadults. American Journal of Clinical Nutrition 1998;68: 311-8.