Vitamin E

Vitam Horm. 2007:76:1-21. doi: 10.1016/S0083-6729(07)76001-6.


The term vitamin E is used to describe eight lipophilic, naturally occurring compounds that include four tocopherols and four tocotrienols designated as alpha-, beta-, gamma-, and delta-. The most well-known function of vitamin E is that of a chain-breaking antioxidant that prevents the cyclic propagation of lipid peroxidation. Despite its antioxidant function, dietary vitamin E requirements in humans are limited only to alpha-tocopherol because the other forms of vitamin E are poorly recognized by the hepatic alpha-tocopherol transfer protein (TTP), and they are not converted to alpha-tocopherol by humans. In attempts to gain a better understanding of vitamin E's health benefits, the molecular regulatory mechanisms of vitamin E have received increased attention. Examples of these mechanisms include: (1) the role of the hepatic alpha-TTP in preferentially secreting alpha-tocopherol into the plasma, (2) phase I and phase II metabolism of vitamin E and the potential impact for drug-vitamin E interactions, and (3) the regulation of biliary excretion of vitamin E by ATP-binding cassette protein(s). It is expected that the continued studies of these regulatory pathways will provide new insights into vitamin E function from which additional human health benefits will evolve.

Publication types

  • Research Support, N.I.H., Extramural
  • Review

MeSH terms

  • Animals
  • Antioxidants* / chemistry
  • Antioxidants* / metabolism
  • Antioxidants* / physiology
  • Biological Transport
  • Chylomicrons / metabolism
  • Humans
  • Rats
  • Vitamin E* / chemistry
  • Vitamin E* / metabolism
  • Vitamin E* / physiology


  • Antioxidants
  • Chylomicrons
  • Vitamin E