Paper
Vitamin E in Human Health and Disease
Published Jan 1, 2008 · M. Clarke, J. Burnett, K. Croft
Critical Reviews in Clinical Laboratory Sciences
192
Citations
4
Influential Citations
Abstract
Vitamin E in nature is comprised of a family of tocopherols and tocotrienols. The most studied of these is α-tocopherol (α-TOH), because this form is retained within the body, and vitamin E deficiency is corrected with this supplement. α-TOH is a lipid-soluble antioxidant required for the preservation of cell membranes, and it potentially acts as a defense against oxidative stress. Many studies have investigated the metabolism, transport, and efficacy α-TOH in the prevention of sequelae associated with cardiovascular disease (CVD). Supplementation with vitamin E is considered to provide health benefits against CVD through its antioxidant activity, the prevention of lipoprotein oxidation, and the inhibition of platelet aggregation. However, the results from large prospective, randomized, placebo-controlled clinical trials with α-TOH have been largely negative. A recent meta-analysis suggests that α-TOH supplements may actually increase all-cause mortality; however, the mechanism for this increased risk is unknown. In vitro studies performed in human cell cultures and animal models suggest that vitamin E might increase the hepatic production of cytochrome P450s and MDR1. Induction of CYP3A4 or MDR1 by vitamin E could potentially lower the efficacy of any drug metabolized by CYP3A4 or MDR1. Other possibilities include an adverse effect of α-TOH on blood pressure in high-risk populations. Because of the wide popularity and use of vitamin E supplements, further research into potential adverse effects is clearly warranted.
Highly CitedVitamin E supplementation may not provide cardiovascular benefits and could potentially increase all-cause mortality, warranting further research into its adverse effects.
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