Vitamin E

written by: Walter S.; article published: year 2008, month 11;

In: Root » » Nutrition

  Share  
|
  PL  |  NL  |  FR  |  ES  |  PT  |  IT  |  DE  |  DK  |  NO  |  SE  |  FI  |  GR  |  JP  |  CN  |  KR  |  RU  |  AE


Vitamin E includes eight naturally occurring compounds divided into tocopherols and tocotrienoles. The most active compound and the most widely available in food is the natural isomer d- (or RRR) α-tocopherol, which accounts for 90% of vitamin E in the human body. Vegetables and seed oils, including soya bean, saffron, sunflower, cereals and nuts, are the main sources. Animal products are poor sources of the vitamin.

Vitamin E is absorbed with fat, transported in the blood largely in low-density lipoproteins (LDL).

An individual's vitamin E requirement depends on the intake of polyunsaturated fatty acids (PUFAs). Since this varies widely, no daily requirement is given in the UK. The requirement stated in the USA is approximately 7-10 mg per day, but average diets contain much more than this. If PUFAs are taken in large amounts, more vitamin E is required.

Function

The biological activity of vitamin E results principally from its antioxidant properties. In biological membranes it contributes to membrane stability. It protects cellular structures against damage from a number of highly reactive oxygen species, including hydrogen peroxide, superoxide and other oxygen radicals. Vitamin E may also affect cell proliferation and growth.

Vitamin E deficiency

The first deficiency to be demonstrated was a haemolytic anaemia described in premature infants. Infant formulations now contain vitamin E.

Deficiency is seen only in children with abetalipoproteinaemia and in patients on long-term parenteral nutrition. The severe neurological deficit (gross ataxia) can be prevented by vitamin E injection.

Plasma or serum levels of α-tocopherol can be measured and should be corrected for the level of plasma lipids by expressing the value as per milligram of plasma lipid or cholesterol.

Share

Disclaimer

1) E-articles is not responsible for the information contained by this article as well for any and all copyright infringements by authors and writers. E-articles is a free information resource. If you suspect this article for any copyright infringement, please read the terms of service and contact us or use the "Report this article" button on this page to investigate the problem.
2) E-articles is not responsible for inaccuracies, falsehoods, or any other types of misinformation this article may contain and will not be liable for any loss or damage suffered by a user through the user's reliance on the information gained here.