Vitamin D levels suboptimal for one in 10 US children

By Reuters Staff

NEW YORK (Reuters Health) - Ten percent of U.S. children have inadequate vitamin D levels, and nearly 5% have levels that place them at risk of frank deficiency, according to data from the National Health and Nutrition Examination Survey (NHANES).

These estimates are considerably reduced from earlier estimates, in large part because new guidelines from the Institute of Medicine (IOM) have substantially lowered the levels that define deficiency (<12 ng/mL) and inadequacy (<16 ng/mL).

Dr. Holly Kramer and colleagues from Loyola University in Maywood, Illinois, used data from NHANES 2003-2006 to assess the prevalence of increased risk of deficiency and increased risk of inadequacy by sex, age group, and body mass index based on the current IOM guidelines.

The study population included 2,877 individuals aged six to 18 years who were predominantly white (60.0%), with 14.3% being African American and 14.0% being Mexican American.

Among these children, 287 were at increased risk of vitamin D deficiency, and 577 were at risk of inadequacy. Most children (n=1,761) met the new standard of adequacy (>20 ng/mL).

After weighting the NHANES data and adjusting it for assay drift, the authors arrived at the following figures: 4.6% of children between six and 18 years are at increased risk of vitamin D deficiency, and 10.3% are at risk of vitamin D inadequacy.

These percentages translate into approximately 2.5 million U.S. children at increased risk of deficiency, 5.5 million at risk of inadequacy, and 40.4 million with adequate vitamin D levels.

Adolescents (14-18 years old) were at the highest risk of deficiency (8.1%) and inadequacy (16.2%), as were obese children (8.2% and 17.8%, respectively), according to the report, online March 12 in the Journal of Pediatric Endocrinology and Metabolism.

The prevalences of increased risk of deficiency and risk of inadequacy were also higher among girls than boys (of any age and body mass index) and among non-white children.

When earlier thresholds of 15 ng/mL and 15-30 ng/mL were used to define vitamin D deficiency and insufficiency, respectively, 4.5 million children have deficient vitamin D levels, and 34.8 million children have insufficient levels, leaving 26.5 million children with levels between 20 and 30 ng/mL.

"A large number of US children have 25-hydroxy-vitamin D levels between 20 and 30 ng/mL and reducing the threshold from 30 ng/mL to 20 ng/mL leads to dramatic reductions in the estimates of US children with insufficient vitamin D levels," the researchers conclude.

SOURCE: http://bit.ly/1jtmMtD

J Pediatr Endocrinol Metab 2014.

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