Prevalence of vitamin D deficiency among healthy adolescents.

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. To determine the prevalence of vitamin D deficiency in healthy adolescents presenting for primary care. A cross-sectional clinic-based sample. An urban hospital in Boston. Three hundred seven adolescents recruited at an annual physical examination to undergo a blood test and nutritional and activity assessments. 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. Seventy-four patients (24.1%) were vitamin D deficient (serum 25OHD level,