The Many Facets of Vitamin D in the Pediatric Population.

Vitamin D is important for skeletal growth, bone mineralization and dental health. Vitamin D deficiency is reported in many countries, may have several causes and can cause rickets in children. A guideline with recommendations of vitamin D supplementation to prevent nutritional rickets was published recently. The vitamin D receptor is present in many cells of the body including cells of the immune system. Many studies have been published on associations between vitamin D deficiency and extra skeletal effects, mainly without proof of causality in intervention studies. This review aims to summarize available evidence of the skeletal and extra-skeletal effects of vitamin D. For the extra-skeletal effects there is proof that vitamin D supplementation can prevent acute respiratory infections in children with vitamin D deficiency and can reduce the rate of asthma exacerbations requiring corticosteroids in children with vitamin D deficiency. The evidence of benefit of vitamin D supplementation is too limited for pediatric patients with other infectious, inflammatory, and autoimmune diseases.