Vitamin D levels in a paediatric population of normal weight and obese subjects

Background Vitamin D exerts pleiotropic effects and few studies are available in the Italian population. Aim of our study was to evaluate vitamin D status in children living in Northern Italy. Methods We studied vitamin D levels in a population of 113 normal weight (NW) and 444 obese (OB) children, prepubertal and pubertal. We considered vitamin D levels >20 ng/ml as normal, but also measured percentage of children with vitamin D levels higher than a cutoff of 30 ng/ml. Results 68.2 % of NW children showed normal levels of vitamin D, while 31.8 % showed a clear vitamin D deficiency. Only 28.3 % showed vitamin D levels higher than 30 ng/ml. Obese children showed 55.6 % of subjects with normal levels of vitamin D and 44.4 % of subjects a status of vitamin D deficiency. Only the 18.9 % showed vitamin D levels higher than 30 ng/ml. Mean vitamin D levels in NW children (27.3 +/- 1.2 ng/ml) were higher than in OB children (21.8 +/- 0.6 ng/ml). No differences have been found between prepubertal and pubertal children in terms of vitamin D levels. Conclusions Our paediatric population demonstrates a low percentage of vitamin D sufficiency. In particular, obese children show only 19 % of subjects with normal levels while almost half of this population shows a clear deficiency. Further studies are needed to support these results and to evaluate the possible metabolic consequences.