The challenge of setting appropriate intake recommendations for vitamin E: considerations on status and functionality to define nutrient requirements.

The main function of vitamin E is to protect against scavenging of reactive oxygen species; it is the primary protective agent against lipid peroxidation. Overt vitamin E deficiency is present only in patients with severe malnutrition and certain chronic diseases. The latest Recommended Dietary Allowance for vitamin E is based on the correlation between hydrogen peroxide-induced erythrocyte lysis and plasma α-tocopherol concentrations (Institute of Medicine, United States), or the prevention of lipid peroxidation (National Nutrition Societies of Germany, Austria and Switzerland, D-A-CH). According to the current recommendations, the reference plasma concentration for vitamin E is 12 - 46 µmol/L (daily intake of 15 - 30 mg α-tocopherol equivalents). Epidemiological studies suggest a beneficial effect of vitamin E on cardiovascular health at a plasma concentration of 30 µmol/L (a daily intake of ~ 50 IU). Vitamin E is also an important micronutrient for maintaining the immune system, especially in the elderly. A workshop was organized with the main objective to propose a concept for developing markers of status, functionality, and health in the field of nutritional research, in order to define desirable vitamin E requirements in healthy individuals.