Tocopherols: biological role, criteria of vitamin supply, physiological need and recommended reference intake

The concept of vitamin E (common name – «tocols») unites a group of 8 lypophilic natural compounds – tocopherols and tocotrienols, existing as four homologues (α-, β-, γ- and δ-) that differ from each other in the chemical structure and properties. According to recent literature data, different tocopherols, having a relatively similar antioxidant activity, nevertheless possess other physiologically significant and often differently directed properties. The α-tocopherol to γ-tocopherol ratio in blood serum is usually 4–5:1, but in patients with cardiovascular diseases it is higher than in healthy individuals, and in patients with metabolic syndrome α-tocopherol concentrations are lower than in healthy individuals. Plasma γ-tocopherol levels serve as a biomarker of a risk for development of cancer and cardiovascular diseases. In the top tertile, concentrations of plasma γ-tocopherol and lower levels of α-tocopherol were associated with a higher risk for asthma, whereas higher levels of α-tocopherol tended to have protective effects. In Russia, vitamin E status is commonly assessed by total concentration of tocopherols in blood plasma. Analysis of available scientific information is suggestive of the expediency to determine particular homologues in blood plasma (first of all, α- and γ-tocopherol) for assessment of vitamin E status. This will permit to individualise the approach to treatment of patients and to maximally optimise vitamin E intake. At present, the physiological need and recommended daily intake have been developed only for α-tocopherol, in perspective these values should be established for its other homologues, too.

Key words: vitamin E, vitamin E status, need, recommended daily intake, tocopherols, tocotrienols, physiological role, effective and safe doses.

For citation: Kodentsova V.M., Risnik D.V. Tocopherols: biological role, criteria of vitamin supply, physiological need and recommended reference intake. Vopr. dietol. (Nutrition). 2018; 8(2): 22–31. (In Russian).

DOI: 10.20953/2224-5448-2018-2-22-31