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What is vitamin E?
Vitamin E is an antioxidant. Antioxidants help protect the body from damage caused by substances called free radicals. Free radicals are natural by-products of the work the body does. If the body is under stress, fighting infection or working hard to break down drugs, more free radicals will be produced. Antioxidants such as vitamin E help protect cells from free radicals. To learn more, see the CATIE Supplement Sheet on antioxidants at www.catie.ca/supple-e.nsf.
Why do people with HIV take vitamin E?
Vitamin E may decrease some of the negative effects of HIV on the immune system and help the immune system fight viral infections more effectively. Here are a few more points about why PHAs use this vitamin:
- To meet increased demand by the body
Studies have found vitamin E deficiencies in some people with HIV/AIDS (PHAs). Research suggests that such deficiencies are more likely to occur the longer a person is living with HIV. Researchers speculate that the stress of fighting HIV and other infections may increase the body’s need for more antioxidants, including vitamin E.
- To increase immune resistance to viral infection
Although many PHAs take supplements of vitamin E, most of the information we have about its impact on the immune system is based on animal and test-tube studies. These studies suggest that excessive amounts of free radicals may trigger some of the unfavourable immune changes seen in PHAs. In studies of mice infected with a virus that causes an AIDS-like disease, vitamin E supplements appeared to slow down the damage caused by this infection.
Several other studies suggest that vitamin E may help fight some viral infections:
- In one study, HIV positive people who took vitamins E and C for three months tended to have lower viral loads, although a clear effect could not be demonstrated.
- Another study tested vitamin E in people with the liver-damaging hepatitis B virus (HBV). The study found that people who took vitamin E were less likely to have signs of virus in their system one year later (53% of those who took vitamin E vs. 18% of those who didn’t) and were more likely to have normal liver function (47% of the vitamin E group vs 6% of the others). Although these results are promising, they need to be confirmed in a larger study.
To protect from free radicals
When the body is working hard to fight infection or break down drugs, more free radicals are produced. These free radicals can damage cells, in the same way that rust can damage a car. Test-tube studies suggest that excess free radicals may also damage the energy producing portions of the cell (called mitochondria). Mitochondrial damage may cause muscle weakness and fatigue, symptoms that are associated both with HIV infection and the use of anti-HIV drugs such as AZT. One group of researchers found evidence of increased free radical damage in people with HIV and in laboratory mice treated with AZT. They also found that high doses of vitamins E and C help protect mouse muscle cells from damage. Other animal studies have suggested that vitamin E might also help protect the bone marrow from drug-associated toxicity, but no human studies in HIV positive people have confirmed these effects.
Available forms
Many different forms of vitamin E are available. Naturopaths usually suggest vitamin E from natural sources. Although the body absorbs both synthetic and natural vitamin E easily, according to the United States Office of Dietary Supplements, the natural form is more active. Natural source vitamin E is often labelled “natural” and contains d-alpha-tocopherol; synthetic forms contain dl-alpha-tocopherol.
Food sources
Vitamin E is made up of several different molecules naturally present in the following foods:
- nuts
- seeds
- whole grains
- vegetable oils
- egg yolks
- green leafy vegetables
Vitamin E must be eaten with some oil or fat to be absorbed.
Dosage
Most adult PHAs taking vitamin E supplements use products containing between 400 and 800 IU (international units) of vitamin E per day, in addition to food sources.
Dietary Reference Intakes (DRI) for most vitamins have been agreed upon by joint committees of Canadian and U.S. scientists. A DRI is the average amount of a nutrient that a healthy person need to stay healthy. The DRI for vitamin E is:
- 15 mg = 22 IU natural vitamin E = 33 IU synthetic vitamin E
Because many people, including PHAs, take high doses of vitamin E for its antioxidant effects, the committee also set an upper level for safe use of vitamin E. The upper level dose for vitamin E is:
- 1,000 mg = 1,500 IU natural vitamin E = 1,100 IU synthetic vitamin E
Side effects
Although side effects from vitamin E are uncommon (even above 1,000 mg), there is an increased risk of spontaneous bleeding, such as nosebleeds or ulcers, with higher doses of vitamin E.
Cautions and concerns
1. Amprenavir
The anti-HIV drug amprenavir (Agenerase) already contains large amounts of vitamin E. People taking amprenavir should not take additional vitamin E supplements.
2. Bleeding
Because of its impact on blood clotting, vitamin E should not be combined with anti-coagulant medications (blood-thinning medications that help prevent clots). People who already have low platelets or other bleeding problems such as haemophilia should not use vitamin E supplements.
References
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Allard JP, Aghdassi E, et al. Effects of vitamin E and C supplementation on oxidative stress and viral load in HIV-infected subjects. AIDS 1998, 12:1653-1659.
Andreone P, Fiorino S, Cursaro C, et al. Vitamin E as treatment for chronic hepatitis B: results of a randomized controlled pilot trial. Antiviral Research 2001;49:75-81.
Anonymous. Food and Nutrition Science Alliance (US). What Consumers Need to Know about Vitamin E, August 2000.
Garcia de la Asuncion J, del Olmo ML, et al. AZT Treatment Induces Molecular and Ultrastructural Oxidative Damage to Muscle Mitochondria. Journal of Clinical Investigation 1998;102(1):4-9.
Geissler RG, Ganser A, et al. In vitro improvement of bone marrow-derived hematopoietic colony formation in HIV-positive patients by alpha-D-tocopherol and erythropoietin. European Journal of Haematology 1994 Oct;53(4):201-6.
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Institute of Medicine. Dietary Reference Intakes for Vitamin C, Vitamin E, Selenium, and Carotenoids, 2000. Available: http://books.nap.edu/catalog/9810.html?onpi_newsdoc041000
Jiang Q, Christen S, Shigenaga MK, Ames BN. gamma-tocopherol, the major form of vitamin E in the US diet, deserves more attention. American Journal of Clinical Nutrition 2001;74(6):714-22.
Lininger SW, Gaby AR et al. Vitamin E (Tocopherol) in The Natural Pharmacy. Prima Publishing, 1999:344-5.
National Institutes of Health (US). Facts about Dietary Supplements: Vitamin E, February 2002.
Odeleye OE, Watson RR. The Potential Role of Vitamin E in the Treatment of Immunologic Abnormalities during Acquired Immune Deficiency Syndrome. Progress in Food and Nutrition Science 1991;15:1-19.
Pacht ER, Diaz P et al. Serum vitamin E decreases in HIV-seropositive subjects over time. Journal of Laboratory and Clinical Medicine 1997;130(3):293-6.
Patrick L. Nutrients and HIV: Part 2–Vitamins A and E, Zinc, B-Vitamins, and Magnesium. Alternative Medicine Review 2000 February;5(1):39-51.
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Wang Y, Huang DS et al. Long-Term Dietary Vitamin E Retards Development of Retrovirus-Induced Disregulation in Cytokine Production. Clinical Immunology and Immunopathology 1994 July;72(1):70-75.
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