Vitamin E – the food stabiliser and important antioxidant in your body (part 4).
In previous parts of this article, we reviewed recommendations and upper limits for Vitamin E uptake. Different forms of Vitamin E were presented and units for calculations amount of Vitamin E in food products and supplements were also explained earlier. In this part, a bioavailability of Vitamin E is discussed and main sources of Vitamin E are listed.
Bioavailability of Vitamin E
During digestion and uptake of Vitamin E are required bile acids and pancreatic enzymes. Absorption increases with the amount of fat in ingested food. For that reason, we have to remember that absorption of Vitamin E from supplements, natural food or fortified products will be minimal if not taken with a fatty meal.
In the body, Vitamin E is transported and distributed by lipoproteins. A concentration of Vitamin E in blood circulation depends on the concentration of lipids and Vitamin C. (1) So, a higher bioavailability of Vitamin E is observed after eating cream cheese than mayonnaise. (2)
If we know, how to increase a bioavailability of Vitamin E, let’s review its potential sources.
Sources of Vitamin E.
a) Natural sources
Particularly high levels of Vitamin E can be found in almonds, asparagus, avocado, nuts, olives, red palm oil, seeds, spinach and other green leafy vegetables, vegetable oils (canola, corn, sunflower, soybean, cottonseed), wheat germ, wholegrain foods and milk.
All eight forms of Vitamin E (alpha-, beta-, gamma-, and delta-Tocopherols and alpha-, beta-, gamma-, and delta-Tocotrienols) occur naturally in mostly plant-based foods but in varying amounts.
More info about amount of Vitamin E in the food you can find in the USDA food composition database at https://ndb.nal.usda.gov/ndb/
b) Dietary supplements.
Most supplements of Vitamin E typically provide only alpha-Tocopherol (and usually in esterified form to prolong its shelf life while protecting its antioxidant properties). However, products containing other Tocopherols and even Tocotrienols are also available. In most cases in supplements is used synthetically produced all-rac-alpha-Tocopherol (commonly labelled as "DL" or "dl"), which as we know contains 8 stereoisomers and is less active than natural Vitamin E (because, as mentioned in previous parts of this article, serum and tissues maintain only four of eight possible stereoisomers). For that reason, people need approximately 50% more of synthetic Vitamin E from dietary supplements or fortified foods to obtain the same amount of the active nutrient as from the natural form.
Most Vitamin E supplements provide ≥100 IU of the alpha-Tocopherol, which is higher than the RDA for this nutrient. Because in general, the average intake of alpha-Tocopherol from food is below the RDAs, special supplementation is needed. For example in the US, the average intake of alpha-Tocopherol from food by adults is 7.2 mg/day versus 15 mg/day of the RDA level. (3) It is also advised a change of Americans’ current dietary practices and includes greater intakes of nuts, seeds, fruit, and vegetables. (4)
Supplementation with high-dose Vitamin E (800-1,200 mg/day) is usually used for medical purposes. For example, it is applied to prevent neurologic deterioration in ataxia with vitamin E deficiency. (5)
If you are a supplier of Vitamin E or supplements with it, present your products to the IngredientsHub expo visitors.
- (Traber MG, Leonard SW, Bobe G, et al. alpha-Tocopherol disappearance rates from plasma depend on lipid concentrations: studies using deuterium-labelled collard greens in younger and older adults. Am J Clin Nutr. 2015; 101(4):752-759).
- (I. Schneider, U. Bindrich and A. Hahn, "The Bioavailability of Vitamin E in Fortified Processed Foods," Food and Nutrition Sciences, Vol. 3 No. 3, 2012, pp. 329-336)
- (Fulgoni VL, 3rd, Keast DR, Bailey RL, Dwyer J. Foods, fortificants, and supplements: Where do Americans get their nutrients? J Nutr. 2011;141(10):1847-1854)
- (Gao X, Wilde PE, Lichtenstein AH, Bermudez OI, Tucker KL. The maximal amount of dietary alpha-Tocopherol intake in U.S. adults (NHANES 2001-2002). J Nutr. 2006;136(4):1021-1026)
- (Traber MG. Vitamin E. In: Ross AC, Caballero B, Cousins RJ, Tucker KL, Ziegler TR, eds. Modern Nutrition in Health and Disease. 11th ed. Philadelphia: Lippincott Williams & Wilkins; 2014:293-304).