Vitamin E function and requirements in relation to PUFA.
Br J Nutr. 2015 Aug 21:1-10. Epub 2015 Aug 21. PMID: 26291567
Vitamin E (��-tocopherol) is recognised as a key essential lipophilic antioxidant in humans protecting lipoproteins, PUFA, cellular and intra-cellular membranes from damage. The aim of this review was to evaluate the relevant published data about vitamin E requirements in relation to dietary PUFA intake. Evidence in animals and humans indicates a minimal basal requirement of 4���5 mg/d of RRR-��-tocopherol when the diet is very low in PUFA. The vitamin E requirement will increase with an increase in PUFA consumption and with the degree of unsaturation of the PUFA in the diet. The vitamin Erequirement related to dietary linoleic acid, which is globally the major dietary PUFA in humans, was calculated to be 0��4���0��6 mg of RRR-��-tocopherol/g of linoleic acid. Animal studies show that for fatty acids with a higher degree of unsaturation, the vitamin E requirement increases almost linearly with the degree of unsaturation of the PUFA in the relative ratios of 0��3, 2, 3, 4, 5 and 6 for mono-, di-, tri-, tetra-, penta- and hexaenoic fatty acids, respectively. Assuming a typical intake of dietary PUFA, a vitamin E requirement ranging from 12 to 20 mg of RRR-��-tocopherol/d can be calculated. A number of guidelines recommend to increase PUFA intake as they have well-established health benefits. It will be prudent to assure an adequate vitamin E intake to match the increased PUFA intake, especially as vitamin E intake is already below recommendations inmany populations worldwide.