title: Prevalence of vitamin D deficiency among healthy adolescents.
abstract: BACKGROUND
  Although vitamin D deficiency has been documented as a frequent problem in studies of young adults, elderly persons, and children in other countries, there are limited data on the prevalence of this nutritional deficiency among healthy US teenagers.
  
  
  OBJECTIVE
  To determine the prevalence of vitamin D deficiency in healthy adolescents presenting for primary care.
  
  
  METHODS
  A cross-sectional clinic-based sample.
  
  
  METHODS
  An urban hospital in Boston.
  
  
  METHODS
  Three hundred seven adolescents recruited at an annual physical examination to undergo a blood test and nutritional and activity assessments.
  
  
  METHODS
  Serum levels of 25-hydroxyvitamin D (25OHD) and parathyroid hormone, anthropometric data, nutritional intake, and weekly physical activity and lifestyle variables that were potential risk factors for hypovitaminosis D.
  
  
  RESULTS
  Seventy-four patients (24.1%) were vitamin D deficient (serum 25OHD level, </=15 ng/mL [</=37.5 nmol/L]), of whom 14 (4.6%) were severely vitamin D deficient (25OHD level, </=8 ng/mL [</=20 nmol/L]). By using a broader definition (25OHD level, </=20 ng/mL [</=50 nmol/L]), 129 patients (42.0%) were vitamin D insufficient. Serum 25OHD levels were inversely correlated with parathyroid hormone levels (r = -0.29), and were 24% lower during winter compared with summer. In a final multivariate model, season, ethnicity, milk and juice consumption, body mass index, and physical activity were significant independent predictors of hypovitaminosis D.
  
  
  CONCLUSIONS
  Vitamin D deficiency was present in many US adolescents in this urban clinic-based sample. The prevalence was highest in African American teenagers and during winter, although the problem seems to be common across sex, season, and ethnicity.
authors.affiliation: Division of Adolescent/Young Adult Medicine, Children's Hospital Boston and Harvard Medical School, Boston, Mass 02115, USA. catherine.gordon@childrens.harvard.edu
authors.forename: Catherine M
authors.initials: CM
authors.lastname: Gordon
authors.forename: Kerrin C
authors.initials: KC
authors.lastname: DePeter
authors.forename: Henry A
authors.initials: HA
authors.lastname: Feldman
authors.forename: Estherann
authors.initials: E
authors.lastname: Grace
authors.forename: S Jean
authors.initials: SJ
authors.lastname: Emans
mesh_terms: D000293:Adolescent; D001900:Boston / Q000453:epidemiology; D002648:Child; D003430:Cross-Sectional Studies; D004032:Diet / Q000706:statistics & numerical data; D019587:Dietary Supplements / Q000706:statistics & numerical data; D005006:Ethnicity / Q000706:statistics & numerical data; D005260:Female; D006801:Humans; D016015:Logistic Models; D008297:Male; D010281:Parathyroid Hormone / Q000097:blood; D015995:Prevalence; D011320:Primary Health Care / Q000706:statistics & numerical data; D012621:Seasons; D017678:Sex Distribution; D014807:Vitamin D / Q000031:analogs & derivatives* / Q000097:blood; D014808:Vitamin D Deficiency / Q000097:blood* / Q000453:epidemiology*; D014815:Vitamins / Q000627:therapeutic use
chemical_list: D010281:Parathyroid Hormone; D014815:Vitamins; D014807:Vitamin D; C104450:25-hydroxyvitamin D