Adequate Intake of Vitamin E Required When Dietary PUFA Intake Increased

24 Aug 2015 --- DSM has published a new paper to further examine vitamin E function and requirements in relation to polyunsaturated fatty acids (PUFAs)[1]. The aim of the manuscript, which is published in the British Journal of Nutrition, is to review the published evidence on the function and requirements of α-tocopherol in relation to the amount of PUFAs in the human diet.

It argues that vitamin E requirement will increase with a rise in PUFA consumption and with the degree of unsaturation of the PUFA in the diet. High intake of PUFAs accompanied by a very low intake of vitamin E may lead to symptoms of vitamin E deficiency.

Vitamin E (α-tocopherol) is recognized as a key essential lipophilic antioxidant in humans, and plays a key role in protecting lipoproteins and cellular and intracellular membranes from damage. The paper highlights that the presence of vitamin E is of key importance in cellular membranes rich in highly unsaturated fatty acids such as docosahexaenoic acid (DHA) and arachidonic acid (ARA). It has been shown that when vitamin E accumulates in DHA-rich, rather unstructured domains, it stabilizes the membrane and protects DHA from oxidative damage[2].

Current daily vitamin E intakes are below recommended levels in more than 90% of North Americans as well as in some European countries[3]. To quantify the vitamin E need, a basal vitamin E level plus an additional vitamin E requirement for dietary PUFAs is often considered. PUFAs are involved in a wide range of processes that are related to physical and mental health in humans, including brain and visual functioning throughout the life course.

“The ratio of vitamin E to PUFA in the human diet is critical and requires deeper examination,” says Dr Daniel Raederstorff, principal scientist, DSM Nutritional Products, Human Nutrition & Health. “However, so far, there has been no consensus on the exact vitamin E to PUFA ratio to determine the vitamin requirement, as it might not be applicable to all types of diet and health status.”

The published human data for a diet with an average content of PUFAs indicates that the additional vitamin E requirement ranges from 0.4 to 0.6 mg RRR-α-tocopherol/g of PUFA in the diet. Using the proposed average of 0.5 mg, the estimated requirement for vitamin E varied from 12 to 20 mg/day for a typical range of dietary PUFA intake.

“Even if more research is needed to precisely define the vitamin E requirement in humans, it is important in view of the critical interactions between vitamin E and PUFAs to ensure adequate intake,” adds Professor Manfred Eggersdorfer, Senior Vice President, Nutrition, Science & Advocacy at DSM and Professor for Healthy Ageing at Groningen University.

References:

1. http://journals.cambridge.org/bjn/PUFA

2. Atkinson J, Harroun T, Wassall SR, Stillwell W, Katsaras J. The location and behavior of alpha-tocopherol in membranes. Mol. Nutr. Food Res. 2010;54(5):641-51. doi: 10.1002/mnfr.200900439.

3. Troesch B, Hoeft B, McBurney M, Eggersdorfer M, Weber P. Dietary surveys indicate vitamin intakes below recommendations are common in representative Western countries. Br. J. Nutr. 2012;108(4):692-8. doi: 10.1017/s0007114512001808.