As observed in the present and previous studies, serum 25(OH)D [27, 28] and adiponectin concentrations [49, 50] are lower in children with obesity compared to children with normal weight, further, the strong inverse association between BMI and adiponectin [51] may have weakened the association in children with overweight/ obesity in our study. The gene discussed is ADIPOQ; the disease is obesity due to melanocortin 4 receptor deficiency.