Vitamin D, parathyroid hormone, and bone mass in adolescents.

This article provides a review of the evidence identifying the factors related to vitamin D status in adolescents. The prevalence of vitamin D deficiency based on 25-hydroxyvitamin D [25(OH)D] of <25 nmol/L ranges from 0 to 32% depending on the season measured and the latitude of the population assessed. The factors that have been reported to affect serum 25(OH)D in adolescents include ethnicity, gender, puberty stage, parathyroid hormone (PTH), dietary vitamin D intake, and sun exposure. Vitamin D supplementation studies are limited to small populations and with supplementation focused on winter months when sunlight may be inadequate. The effects of vitamin D status and supplementation on bone assessment provide varied results. Differences in study design, modalities of bone assessment, and stage of puberty could contribute to disparate findings. Overall, the results from the available literature provide more questions than answers concerning the role of vitamin D in bone accrual in adolescents.