Effects of vitamin D supplementation on insulin resistance and cardiometabolic risk factors in children with metabolic syndrome: a triple-masked controlled trial

Objective: this triple-masked controlled trial aimed to assess the effects of vitamin D supplementation on insulin resistance and cardiometabolic risk factors in obese children and adolescents. Methods: the study comprised 50 participants, aged 10 to 16 years, who were randomly assigned into two groups of equal number. In this 12-week trial, one group received oral vitamin D (300,000 IU) and the other group received placebo. Cardiometabolic risk factors, insulin resistance, and a continuous value of metabolic syndrome (cMetS) were determined. Statistical analysis was conducted after adjustment for covariate interactions. Results: overall, 21 patients in the vitamin D group and 22 in the placebo group completed the trial. No significant difference was observed in the baseline characteristics of the two groups. After the trial, in the vitamin D group, serum insulin and triglyceride concentrations, as well as HOM - IR and C-MetS decreased significantly, both when compared with the baseline and with the placebo group. No significant difference was observed when comparing total cholesterol, LDL-C, HDL-C, fasting blood glucose, and blood pressure. Conclusion: the present findings support the favorable effects of vitamin D supplementation on reducing insulin resistance and cardiometabolic risk factors in obese children. (C) 2013 Sociedade Brasileira de Pediatria. Published by Elsevier Editora Ltda. All rights reserved.