Vitamin E

Vitamin E is a fat-soluble vitamin that is well known for its antioxidant properties.

Vitamin E is the most effective, fat-soluble antioxidant known to occur in the human body. It makes the specialised membranes that enclose the body cells much more stable and helps to protect the structures inside the cells, such as DNA, from damage by free radicals and other harmful chemicals.

Tocopherols and tocotrienols are two groups of molecules comprising Vitamin E. There are four natural tocopherols and tocotrienols, alpha-, beta-, gamma- and delta. Of the eight naturally occurring forms of vitamin E, it appears that only naturally occurring alpha-tocopherol (commonly known as d-alpha-tocopherol) is maintained in the human blood circulation. Synthetic alpha-tocopherol is commonly known as d1-alpha-tocopherol.

To obtain Vitamin E from the diet, a person must be able to digest and absorb fats properly. This is because Vitamin E is a fat-soluble vitamin. Vitamin E is essential for the proper functioning of many different body systems. It is required by the nervous system to maintain many of the nerves in the body and spinal cord in good working order; it is necessary for the normal production of red blood cells; it is essential for normal reproduction; it is required for the health of the muscle cells and it is required for the proper function of the cells in the heart. Vitamin E may also help reduce the risks of atherosclerosis (the formation of fatty plaques on the walls of the blood vessels that causes heart disease).

Vitamin E is believed to be safe when taken in high doses by most people. People who are taking warfarin or other anti-clotting drugs, herbs or nutritional supplements should seek medical advice before taking Vitamin E supplements, as Vitamin E can interfere with blood clotting time.

MEDICAL USE

Heart Disease. Vitamin C and vitamin E, taken in combination, help to stabilise LDL cholesterol in the body. This may help to reduce the risk of atherosclerosis. Clinical studies indicate that this benefit may be greater in smokers than non-smokers. Vitamin E has been shown in clinical trials to have a protective effect on the heart and a blood pressure lowering effect in cases of mild Hypertension.

Stroke. Vitamin E may also reduce the chances of stroke in people who are considered to be at high risk of suffering this condition. Vitamin E may also improve resistance against infection by boosting the immune system's responses.

Alzheimer's disease. Vitamin E may also help to slow the progression of Alzheimer's Disease.

DEFICIENCY

The main signs of Vitamin E deficiency are reproductive failure, muscular wasting, anaemia, poor immunity and problems with the nervous system such as poor reflexes, poor coordination of the eye muscles and unsteadiness when walking. Vitamin E deficiency may also contribute to cardiovascular diseases, including atherosclerosis, as well as an increased risk of certain cancers.

SOURCES

Vitamin E is found in plants, animals and in some green, brown and blue/green algae. The richest sources of the vitamin are found in unrefined edible vegetable oil, including wheat germ, safflower, sunflower, cottonseed, canola and olive oils. In these oils, approximately 50 percent of the tocopherol content is in the form of alpha-tocopherol. Soybean and corn oils contain about ten times more gamma-tocopherol than alpha-tocopherol. Palm, rice bran and coconut oils are rich sources of tocotrienols. Alpha-tocopherol is the major form of vitamin E in animal products and is found mainly in the fatty portion of the meat. Other foods containing vitamin E include unrefined cereal grains, fruits, nuts and vegetables.

DOSAGE

The recommended dietary intake (RDI) for Vitamin E (in the form of dl-alpha tocopherol) is 10 mg per day for adult males and 7 mg per day for adult females, although women that are lactating require 9.5 mg per day. Note that 1 international unit (1 IU) of Vitamin E is equivalent to 1 mg of dl-alpha tocopheryl acetate.