Serum 25-hydroxyvitamin D levels among US children aged 1 to 11 years: do children need more vitamin D?

OBJECTIVE Single-center studies suggest [corrected] that hypovitaminosis D is widespread. Our objective was to determine the serum levels of 25-hydroxyvitamin D (25[OH]D) in a nationally representative sample of U.S. [corrected] children ages 1-11 [corrected] years. METHODS Data were obtained from the 2001-2006 National Health and Nutrition Examination Survey (NHANES). [corrected] Serum 25(OH)D levels was [corrected] determined by radioimmunoassay and categorized as <25 nmol/L, [corrected] <50 nmol/L, [corrected] and <75 nmol/L. National estimates were obtained by using assigned patient visit weights and reported with 95% confidence intervals (95% CI). [corrected] RESULTS During [corrected] 2001-2006, the mean serum 25(OH)D level for U.S. children ages 1 to 11 years was 68 nmol/L (95% CI, [corrected] 66-70). Children ages 6-11 [corrected] years had lower mean levels of 25(OH)D (66 nmol/L 95% CI, [corrected] 64-68) compared to [corrected] children ages 1-5 [corrected] years (70 nmol/L 95% [corrected] CI, 68-73). [corrected] Overall, the prevalence of <25 nmol/L [corrected] was 1% (95% CI, 0.7-1.4), <50 nmol/L was 18% (95% CI, [corrected] 16-21), and <75 nmol/L was 69% (95% CI, [corrected] 65-73). The prevalence of [corrected] 25(OH)D [corrected] <75 nmol/L was higher among ages [corrected] 6-11 [corrected] years (73%) compared to ages [corrected] 1-5 [corrected] years (63%); females [corrected] (71%) compared to males [corrected] (67%); and non-Hispanic black (92%) and Hispanic (80%) [corrected] compared to [corrected] non-Hispanic whites [corrected] (59%). CONCLUSIONS Based on [corrected] a nationally representative sample of U.S. children aged 1-11 [corrected] years, millions of children may have suboptimal levels of 25(OH)D, especially non-Hispanic black and Hispanic children. More data in children are needed not only to understand better the health implications of specific serum levels of 25(OH)D but also to determine the appropriate vitamin D supplement requirements for children.