Background: Obese adolescents are at a greater risk for vitamin D deficiency because the vitamin is thought to be sequestered by excess adipose tissue. Poor vitamin D status has been associated with a higher prevalence of the metabolic syndrome and/or type 2 diabetes in both adults and adolescents. Objective: To determine in obese adolescents the efficacy and safety of 4000 IU/day of vitamin D3; and if subsequent increased circulating concentrations of 25 hydroxyvitamin D [(25(OH)D] are...

Background: Currently, there is a lack of clarity in the literature as to whether there is a definitive difference between the effects of vitamins D2 and D3 in the raising of serum 25-hydroxyvitamin D [25(OH)D]. Objective: The objective of this article was to report a systematic review and meta-analysis of randomized controlled trials (RCTs) that have directly compared the effects of vitamin D2 and vitamin D3 on serum 25(OH)D concentrations in humans. Design: The ISI Web of Knowledge...