Vitamin D and Glucose Metabolism in Pediatrics

The discovery that the vitamin D receptor is expressed in more than 30 tissues indicates
that the physiologic functions of vitamin D are much broader than its well-known role in the
regulation of calcium absorption and bone metabolism. There is evidence that vitamin D is
involved in the pathogenesis of cancer, cardiovascular disease, multiple sclerosis, and type
I diabetes. Recent epidemiological evidence points to a strong association between vitamin D
insufficiency and insulin resistance, the metabolic syndrome, and type II diabetes. The
investigators would like to examine the role of vitamin D in the development of insulin
resistance in overweight children and adolescents, which represent a high risk population
for cardiovascular and metabolic complications. The investigators propose a prospective
randomized clinical trial of vitamin D supplementation in overweight, insulin resistant,
vitamin D deficient children. The investigators objective is to assess if changes in insulin
resistance, fasting lipid profiles, blood pressure, and inflammatory markers occur in these
patients post treatment with vitamin D. Additionally, concomitant changes in calcium and
bone metabolism after vitamin D treatment will be evaluated. This is because, contrary to
adults, the optimal vitamin D concentrations that regulate calcium and bone metabolism have
not been established in pediatrics.