Scottish Trace Element and Micronutrient Reference Laboratory

Scotland's specialised laboratory for trace elements and vitamins in health and disease

Vitamin E

Trace Elements

Vitamins

Specialised services

In plasma, vitamin E is bound to lipoproteins and is present mainly in the form of -tocopherol which is also of most relevance nutritionally. Its main function is as an antioxidant eg. protecting oxidation of unsaturated fatty acids and so maintaining the integrity of cell membranes, and possibly protecting against cardiovascular disease by preventing LDL oxidation. The activity of vitamin E is lost when it neutralizes a free radical but it can be regenerated by vitamin C.

Deficiency of vitamin E may result in neurological disease manifested by irritability, oedema, haemolytic anaemia, impaired co-ordination and balance, and muscle weakness. Deficiency is unusual except in cases of fat malabsorption, abetalipoproteinaemia, long term TPN, and in low birth weight infants.

The prevalence of cardiovascular disease is lower in those individuals whose dietary intake of vitamin E is higher. However, intervention studies have failed to demonstrate protection from heart attacks and death in patients with heart disease when vitamin E supplements are given. Similarly the prevalence of breast and lung cancer is not reduced when vitamin E is given.

There seems to be little toxicity of vitamin E until intake is very high when the risk of haemorrhage is increased.

Since plasma α-tocopherol is bound to lipoproteins and so the concentration is affected both by cholesterol concentrations and the acute phase response. For this reason plasma vitamin E is corrected for cholesterol concentrations so giving a good indicator of tissue stores even during the acute phase response.

Sample Requirements, Reference Values, & General Information