| Item |
Information |
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Drug Groups
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approved; nutraceutical |
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Description
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A generic descriptor for all tocopherols and tocotrienols that exhibit alpha-tocopherol activity. By virtue of the phenolic hydrogen on the 2H-1-benzopyran-6-ol nucleus, these compounds exhibit varying degree of antioxidant activity, depending on the site and number of methyl groups and the type of isoprenoids. [PubChem] |
| Indication |
Vitamin E, known for its antioxidant activities, is protective against cardiovascular disease and some forms of cancer and has also demonstrated immune-enhancing effects. It may be of limited benefit in some with asthma and rheumatoid arthritis. It may be helpful in some neurological diseases including Alzheimer's, some eye disorders including cataracts, and diabetes and premenstrual syndrome. It may also help protect skin from ultraviolet irradiation although claims that it reverses skin aging, enhances male fertility and exercise performance are poorly supported. It may help relieve some muscle cramps. |
| Pharmacology |
Vitamin E has antioxidant activity. It may also have anti-atherogenic, antithrombotic, anticoagulant, neuroprotective, antiviral, immunomodulatory, cell membrane-stabilizing and antiproliferative actions. Vitamin E is a collective term used to describe eight separate forms, the best-known form being alpha-tocopherol. Vitamin E is a fat-soluble vitamin and is an important antioxidant. It acts to protect cells against the effects of free radicals, which are potentially damaging by-products of the body's metabolism. Vitamin E is often used in skin creams and lotions because it is believed to play a role in encouraging skin healing and reducing scarring after injuries such as burns. There are three specific situations when a vitamin E deficiency is likely to occur. It is seen in persons who cannot absorb dietary fat, has been found in premature, very low birth weight infants (birth weights less than 1500 grams, or 3½ pounds), and is seen in individuals with rare disorders of fat metabolism. A vitamin E deficiency is usually characterized by neurological problems due to poor nerve conduction. Symptoms may include infertility, neuromuscular impairment, menstrual problems, miscarriage and uterine degradation. Preliminary research has led to a widely held belief that vitamin E may help prevent or delay coronary heart disease. Antioxidants such as vitamin E help protect against the damaging effects of free radicals, which may contribute to the development of chronic diseases such as cancer. It also protects other fat-soluble vitamins (A and B group vitamins) from destruction by oxygen. Low levels of vitamin E have been linked to increased incidence of breast and colon cancer. |
| Affected Organisms |
| • |
Humans and other mammals |
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| Biotransformation |
Hepatic. |
| Absorption |
50 to 80% absorbed from gastrointestinal tract. |
| Protein Binding |
Bound to beta-lipoproteins in blood. |
| References |
| • |
Iuliano L, Micheletta F, Maranghi M, Frati G, Diczfalusy U, Violi F: Bioavailability of vitamin E as function of food intake in healthy subjects: effects on plasma peroxide-scavenging activity and cholesterol-oxidation products. Arterioscler Thromb Vasc Biol. 2001 Oct;21(10):E34-7.
[Pubmed]
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Miller ER 3rd, Pastor-Barriuso R, Dalal D, Riemersma RA, Appel LJ, Guallar E: Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern Med. 2005 Jan 4;142(1):37-46. Epub 2004 Nov 10.
[Pubmed]
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Horwitt MK, Elliott WH, Kanjananggulpan P, Fitch CD: Serum concentrations of alpha-tocopherol after ingestion of various vitamin E preparations. Am J Clin Nutr. 1984 Aug;40(2):240-5.
[Pubmed]
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Rumbold AR, Crowther CA, Haslam RR, Dekker GA, Robinson JS: Vitamins C and E and the risks of preeclampsia and perinatal complications. N Engl J Med. 2006 Apr 27;354(17):1796-806.
[Pubmed]
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Poston L, Briley AL, Seed PT, Kelly FJ, Shennan AH: Vitamin C and vitamin E in pregnant women at risk for pre-eclampsia (VIP trial): randomised placebo-controlled trial. Lancet. 2006 Apr 8;367(9517):1145-54.
[Pubmed]
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Linus Pauling Institute /
[Link]
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