Vitamin E (Tocopherol)
Chemically vitamin E designates the group of compounds (tocol and tocotrienol derivatives) which exhibits qualitatively the biological activity of alpha tocopherol.
Chemical characterstics of vitamin E
Biological activity associated with vitaminE is exhibited by four compounds designated as alpha,beta,gamma and delta tocopherols. Of these, alpha tocopherol is the most important because of its biological activity and occurance.
Tocopherols are oily liquids at room temperature. High temperature and acidic ph donot affect its stability but its oxidation occurs in the presence of iron or rancid fat.
Tocopherols act as antioxidants.Delta tocopherol shows the highest antioxidant power.
Digestion and absorption of vitamin E
Fat and bile salts facilitate absorption of vitamin E in the intestinal wall. The vitamin is then carried to the liver. However, very little vitamin E is transferred to the infant across the placenta.
Functions of vitamin E
- Vitamin E converts the free radical into less reactive and non-toxic form.
- It works as protector against oxidation.
- In the membranous part of the cell vitamin E integrates with phospholipids, cholestrol, triglycerides- the three main structural elements of membranes.
In general, vitamin E plays an important role in maintaining stability and integrity of cell membrane.
Deficiency symptoms of vitamin E
In severe deficiency there is increased haemolysis of the red blood cells, creatinuria, deposition of brownish ceroid pigment in smooth muscle and development of muscular dystrophy.
Sources of vitamin E
Good food sources of Vitamin E are (in descending order):
Vitamin E has been claimed to have some anti-aging effects, both taken orally and applied on the skin.
Excellent sources of vitamin E include: mustard greens, chard, sunflower seeds, and turnip greens. Very good sources include almonds and spinach.
The best sources of vitamin E are vegetable oils such as sunflower, canola, corn, soybean and olive oil. Nuts, sunflower seeds and wheat germ are also good sources. Other sources of vitamin E are whole grains, fish, peanut butter, and green, leafy vegetables.