Vitamin E

Vitamin E is a fat-soluble dietary vitamin necessary for normal reproduction, muscular development, resistance of erythrocytes to haemolysis, and various other biochemical functions in humans and animals. Also, it can act as an antioxidant. "Vitamin E" is in fact a group which entails eight naturally occurring compounds, tocopherols and tocotrienols, of which d-alpha-tocopherol is the most widely available and the most biologically active.

Sources of vitamin E include fresh nuts, wheat germ seed oils, and green leafy vegetables. Animal products are generally poor sources. The recommended daily allowance is 10mg and 8mg in men and women, respectively.

Absorption depends on the digestion and absorption of fat. Free tocopherols passively enter lymphatic circulation, whereas metabolites and a small amount of vitamin E enter the portal circulation. Vitamin circulating in the blood is principally bound to low-density and high-density lipoprotein (LDL and HDL).

Vitamin E is stored in the liver, adipose tissue, muscle, pituitary gland, testes and adrenals.

Note that there is evidence that suggests that high-dose vitamin E supplementation is associated with an increased all-cause mortality (1).

Reference:

1. Miller ER III et al. Meta-analysis: high-dosage vitamin E supplementation may increase all-cause mortality. Ann Intern Med 2005;142: 37-46