Vitamin E content
Vitamin E is a fat-soluble vitamin with several forms, but alpha-tocopherol is the only one used by the human body. Its main role is to act as an antioxidant, scavenging loose electrons—so-called “free radicals”—that can damage cells.
Vitamin E is a group of eight fat soluble compounds that include four tocopherols and four tocotrienols.[1][2] Vitamin E deficiency, which is rare and usually due to an underlying problem with digesting dietary fat rather than from a diet low in vitamin E,[3] can cause nerve problems.[4] Vitamin E is a fat-soluble antioxidant which may help protect cell membranes from reactive oxygen species.[2][4] Worldwide, government organizations recommend adults consume in the range of 3 to 15 mg per day. As of 2016, consumption was below recommendations according to a worldwide summary of more than one hundred studies that reported a median dietary intake of 6.2 mg per day for alpha-tocopherol.[5]
Population studies suggested that people who consumed foods with more vitamin E, or who chose on their own to consume a vitamin E dietary supplement, had lower incidence of cardiovascular diseases, cancer, dementia, and other diseases. However, placebo-controlled clinical trials using alpha-tocopherol as a supplement, with daily amounts as high as 2,000 mg per day, could not always replicate these findings.[2] In the United States vitamin E supplement use peaked around 2002, but has declined by more than half by 2006. The authors theorized that declining use may have been due to publications of large placebo-controlled studies that showed either no benefits or actual negative consequences from high-dose vitamin E.[6][7][8]
Why its matter a lot
methyl group. For gamma(γ)-tocopherol: R1 = H, R2 = methyl group, R3 = methyl group. For delta(δ)-tocopherol: R1 = H, R2 = H, R3 = methyl group. The same configurations exist for the tocotrienols, except that the hydrophobic side chain has three carbon-carbon double bonds whereas the tocopherols have a saturated side
Stereoisomers[edit]
In addition to distinguishing tocopherols and tocotrienols by position of methyl groups, the tocopherols have a phytyl tail with three chiral points or centers that can have a right or left orientation. The naturally occurring plant form of alpha-tocopherol is RRR-α-tocopherol, also referred to as d-tocopherol,