vitamin E

About vitamin E

Vitamin E is a generic term for tocopherols and . Vitamin E is a family of -, -, -, and - and corresponding four tocotrienols. Vitamin E is a fat-soluble that stops the production of reactive oxygen species formed when fat undergoes oxidation. Of these, -tocopherol (also written as ) has been most studied as it has the highest .
It has been claimed that -tocopherol is the most important lipid-soluble antioxidant, and that it protects from oxidation by reacting with lipid radicals produced in the . This would remove the intermediates and prevent the reaction from continuing. The oxidised -tocopheroxyl radicals produced in this process may be recycled back to the active reduced form through reduction by other antioxidants, such as , or . However, the importance of the antioxidant properties of this molecule at the concentrations present in the body are not clear and it is possible that the reason why vitamin E is required in the diet is unrelated to its ability to act as an antioxidant.. Other forms of vitamin E have their own unique properties. For example, -tocopherol (also written as gamma-tocopherol) is a that can react with mutagens.
However, the roles and importance of all of the various forms of vitamin E are presently unclear, and it has even been suggested that the most important function of vitamin E is as a , and that it has no significant role in antioxidant metabolism.
So far, most studies about vitamin E have supplemented using only the synthetic alpha-tocopherol, but doing so leads to reduced serum gamma- and delta-tocopherol concentrations. Moreover, a 2007 clinical study involving synthetic alpha-tocopherol concluded that supplementation did not reduce the risk of major cardiovascular events in middle aged and older men. For more info, read article .
Compared with tocopherols, are poorly studied. Less than 1% of PubMed papers on vitamin E relate to tocotrienols. Current research direction are starting to give more prominence to the tocotrienols, the lesser known but more potent antioxidants in the vitamin E family. have specialized roles in protecting from damage, cancer prevention and cholesterol reduction by inhibiting the activity of HMG-CoA reductase[16-1];-tocotrienol blocks processing of sterol regulatory elementbinding proteins (SREBPs)[16-1].
Oral consumption of is also proven to protect against stroke-associated brain damage in vivo. Disappointments with outcomes-based clinical studies testing the efficacy of -tocopherol need to be handled with caution and prudence recognizing the untapped opportunities offered by the other forms of natural vitamin E. Toxicity studies of a specific form of tocopherol in excess should not be used to conclude that high-dosage vitamin E supplementation may increase all-cause mortality. Such conclusion incorrectly implies that tocotrienols are toxic as well under conditions where tocotrienols were not even considered. For more info, read article .