Vitamin D status and its associations with components of metabolic syndrome in healthy children

Aim: High prevalence of vitamin D insufficiency/deficiency has been reported in populations of different countries. The aim of this cross-sectional study was to determine the prevalence and association of vitamin D status with components of metabolic syndrome. Methods: Lipid profile indices, anthropometric indices [body mass index and waist circumference (WC)], insulin resistance index (HOMA-IR), systolic blood pressure (SBP), diastolic blood pressure (DBP), C-reactive protein, intact parathyroid hormone (iPTH), and serum 25-hydroxy-vitamin D [25(OH) D] concentration were evaluated in 297 healthy schoolchildren aged 7-11 years. Multivariate linear regression was used to determine independent predictors associated with low serum 25(OH) D concentrations. Results: The mean serum 25(OH) D concentration was 14.12 +/- 8.20 ng/mL (35.3 +/- 20.5 nmol/L); 96% of children had low serum 25(OH) D levels, 31.0% were deficient, and 65.0% had insufficient levels of 25(OH) D. Vitamin D deficiency was higher in girls (chi(2) = 13.66; p = 0.00); 25(OH) D level was negatively associated with WC, HOMA-IR, SBP, DBP, and iPTH. In the multivariate model, WC, DBP, and HOMA-IR were significant independent predictor of low 25(OH) D concentrations. Conclusion: The prevalence of low vitamin D level in the studied healthy children was high and it is correlated with some components of metabolic syndrome. Outdoor activity for optimum sun exposure and additional studies are needed to evaluate the underlying metabolic syndrome components and hypovitaminosis D complications.