Vitamin E is a fat-soluble vitamin. It exists in eight different forms, each with its own pattern of activity in the body. For our purposes, we'll focus on the alpha-tocopherol form, which is the most active form of Vitamin E in humans.

This is the type of Vitamin E you purchase in supplement form.

Vitamin E is another antioxidant (like Vitamin C) which protects our cells against the effects of free-radicals, which are free-floating chemicals that occur as a byproduct of energy metabolism. These free radicals can damage cells, and may accelerate the development of cancer and heart disease.

Vitamin E has also been shown to play a role in immune system maintenance and DNA repair.

Good sources of vitamin E include dark, leafy green vegetables, vegetable oils, and nuts and fortified cereals.