Treatment Study of Vitamin D Deficiency in Adolescents

To compare the efficacy of two high dose vitamin D3 regimens (5,000 IU daily vs. 50,000 IU weekly) used clinically for the treatment of vitamin D deficiency versus a low dose of vitamin D3 used for supplementation (1,000 IU daily) in a clinical sample of predominantly Hispanic and black adolescents with vitamin D deficiency \[25(OH)D level \<20 ng/ml\] by assessing change in 25(OH)D levels before and after 8 weeks of treatment. To compare the effects of vitamin D repletion \[25(OH)D level \>20 ng/mL\] on selected musculoskeletal, cardiometabolic and immune markers in predominantly Hispanic and black adolescents with vitamin D deficiency \[25(OH)D level \< 20 ng/mL\]. Hypothesis 1: Increase in vitamin D level will be associated with improvement in musculoskeletal, cardiometabolic, and immune markers including blood pressure, waist circumference, musculoskeletal symptoms, asthma severity and hand-grip strength.