Study Questions Vitamin E Status of Americans
Vitamin E (α-tocopherol) is an essential lipophilic antioxidant that plays a key role in protecting lipoproteins and membranes (cellular and intracellular) from free radical damage. Vitamin E has been identified as a ‘shortfall nutrient’ because >90% of Americans are not consuming recommended amounts of vitamin E.
Based on serum α-tocopherol concentrations measured by federal agency laboratories in a nationally representative sampling of Americans (NHANES 2003-2006), McBurney and colleagues report that 93% of 20-30 year olds, 81% of 31-50 year olds, and 81% of individuals 51+ years have suboptimal vitamin E status. Lower proportions are observed among individuals reporting dietary supplement use (79% of 20-30y olds, 54% of 31-50y olds, and 29% for those over 51 years). The prevalence of not meeting the criterion of adequacy (30 µmol α-tocopherol/L) was higher among younger populations. Females were more likely to have low vitamin E status than males. Non-hispanic blacks (77.5%) and Mexican Americans (62.2%) were more likely to have low vitamin E status than non-Hispanic whites (57.2%).
The criterion of adequacy (30 µmol/L) is the α-tocopherol concentration associated with the estimated average requirement (EAR) and the lowest risk of mortality in the Alpha-Tocopherol Beta-Carotene (ATBC) Cancer Prevention Study with almost 30,000 individuals.
Current vitamin E intakes from the diet are below recommended levels for the majority of adults living in western European countries. Because foods naturally-rich in vitamin E are not being consumed, vitamin E intake is low unless the diet is supplemented.
The authors speculate that low vitamin E status may contribute to age-related changes in reproductive, brain, and liver function. From the supplemental data provided from 3 vitamin E meta-analyses, it is apparent that baseline vitamin E concentrations were higher in individuals volunteering for RCTs conducted in the second half of the 20th century than currently observed in the population.
As senior author, Dr Saurabh Mehta, a faculty member at Cornell University says: “These findings indicate that it is important to conduct further research to elucidate the association of serum α-tocopherol concentrations with specific health outcomes.”
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