Hypovitaminosis D among healthy children in the United States: a review of the current evidence.
OBJECTIVE
To review the published literature on serum 25-hydroxyvitamin D concentrations in US children.


METHODS
Articles were identified by searching MEDLINE using 25-hydroxyvitamin D, vitamin D, hypovitaminosis D, vitamin D insufficiency, vitamin D deficiency, children, and adolescents as key words and by screening references from original studies.


METHODS
Studies were included if they fulfilled the following a priori criteria: contained a well-defined sample of children, included only healthy children, presented data on serum 25-hydroxyvitamin D concentrations, were published in the past 10 years, and were conducted in the United States.


METHODS
Serum 25-hydroxyvitamin D concentrations and prevalence of low vitamin D status (hypovitaminosis D).


RESULTS
Fourteen articles fulfilled the criteria. There were no consistent definitions of hypovitaminosis D; values corresponding to vitamin D deficiency ranged from less than 5 ng/mL to less than 12 ng/mL, and those for vitamin D insufficiency ranged from less than 10 ng/mL to less than 32 ng/mL (to convert 25-hydroxyvitamin D concentrations to nanomoles per liter, multiply by 2.496). The following assays were used: radioimmunoassay (7 studies), competitive binding protein assay (3 studies), automated chemiluminescence protein-binding assay (3 studies), and enzyme-linked immunosorbent assay (1 study). Breastfed infants in winter who did not receive vitamin D supplementation were the most severely vitamin D deficient (78%). Estimates of the prevalence of hypovitaminosis D ranged from 1% to 78%. Older age, winter season, higher body mass index, black race/ethnicity, and elevated parathyroid hormone concentrations were associated with lower 25-hydroxyvitamin D concentrations.


CONCLUSIONS
Although overt vitamin D deficiency is no longer common in US children, lesser degrees of vitamin D insufficiency are widespread.
Rovner
Alisha J
AJ
Division of Epidemiology, Statistics and Prevention, Eunice Kennedy Shriver National Institute of Child Health and Human Development, 6100 Executive Blvd, Room 7B13A, MSC 7510, Rockville, MD 20852, USA. rovneral@mail.nih.gov
O'Brien
Kimberly O
KO
D000293:Adolescent; D000328:Adult; D001667:Binding, Competitive; D002118:Calcium / Q000378:metabolism; D002648:Child; D002675:Child, Preschool; D004797:Enzyme-Linked Immunosorbent Assay; D005260:Female; D006304:Health Status; D006801:Humans; D007223:Infant; D007231:Infant, Newborn; D008163:Luminescent Measurements; D008297:Male; D009752:Nutritional Status; D010758:Phosphorus / Q000378:metabolism; D011863:Radioimmunoassay; D012307:Risk Factors; D014481:United States / Q000453:epidemiology; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology*
D014807:Vitamin D; D010758:Phosphorus; C104450:25-hydroxyvitamin D; D002118:Calcium