Will the real vitamin D figures please stand up?

Using guidelines issued by the Institute of Medicine (IOM), about 1 in every 10 US children is at risk of vitamin D inadequacy and about 1 in 20 is at risk of deficiency, according to a new report. These figures are drastically lower than previous estimates.

The new study led by researchers at Loyola University Chicago Stritch School of Medicine includes 2877 children and adolescents aged between 6 and 18 years who participated in the National Health and Nutrition Examination Survey of 2003 to 2006.

According to the IOM guidelines, those at risk of deficiency have serum 25(OH)D levels less than 12 ng/mL. Those at risk for inadequacy have serum levels below 16 ng/mL, and those with adequate vitamin D exposure have serum 25(OH)D levels greater than 20 ng/mL.

Using these parameters, the researchers found that 4.61% of the children and adolescents studied-which would translate to an estimated 2.5 million in the population at large-are at increased risk of deficiency. They found that another 10.3%, or an estimated 5.5 million in the population, are at risk of inadequate vitamin D.

However, the Endocrine Society and other expert bodies have suggested that 30 ng/mL is a better cutoff to maintain proper bone health. Using that figure, the Loyola researchers explain that nearly 70% of children and adolescents between the ages of 1 and 21 would have deficient or insufficient levels of vitamin D. This puts those children with levels between 20 ng/mL and 30 ng/mL at particular risk. Using 1 set of guidelines, these children would receive supplementation and using another, they would not. 

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