Vitamin D in childhood and adolescence: an expert position statement.

UNLABELLED: Vitamin D is a key hormone in the regulation of calcium and phosphorus metabolism and plays a pivotal role in bone health, particularly during pediatric age when nutritional rickets and impaired bone mass acquisition may occur. Great interest has been placed in recent years on vitamin D's extraskeletal actions. However, while recent data suggest a possible role of vitamin D in the pathogenesis of several pathological conditions, including infectious and autoimmune diseases, the actual impact of vitamin D status on the global health of children and adolescents, other than bone, remains a subject of debate. In the meantime, pediatricians still need to evaluate the determinants of vitamin D status and consider vitamin D supplementation in children and adolescents at risk of deficiency. This review is the result of an expert meeting that was held during the congress "Update on vitamin D and bone disease in childhood" convened in Pisa, Italy, in May 2013. CONCLUSION: The collaboration of the international group of experts produced this "state of the art" review on vitamin D in childhood and adolescence. After dealing with vitamin D status and its determinants, the review outlines the current debate on vitamin D's health benefits, concluding with a practical approach to vitamin D supplementation during childhood and adolescence. WHAT IS KNOWN: • Vitamin D deficiency is a worldwide health problem. • Vitamin D deficiency affects not only musculoskeletal health but also a potentially wide range of acute and chronic diseases. What is New: • We reviewed the literature focusing on randomized controlled trials of vitamin D supplementation during childhood and adolescence. • This review will help pediatricians to appreciate the clinical relevance of an adequate vitamin D status and it will provide a practical approach to vitamin D supplementation.

[Vitamin D in childhood]. / La vitamine D en pédiatrie.

Infantile Nutritional Rickets has disappeared almost completely in France since 1992 as vitamin D enriched formula availability and previous vitamin D supplementation of infants. The search of evocative symptoms of rickets should be a routine procedure in infants, in particular in case of insufficient vitamin D intake i.e. breastfeeding, and the possibility of vitamin D resistant rickets. Hypocalcaemia occurs not only at the first but also the advanced stages of vitamin D deficiency, and may be responsible for severe cardiologic, neurologic or respiratory complications with possibility of infant death. For the young children between 1 and 5 years and for adolescents, vitamin D insufficiency is responsible for poor skeletal mineralization, loss of bone strength, and a reduction of peak of bone mineral mass at the end of puberty. The new Dietary Reference Intakes (DRI, 2011) increased greatly the Recommended Dietary allowances (RDA) from 200 to 600 IU/d (15 µg/d) for individuals from 1 to 70 years of age. These levels are not reached in winter, even in countries, like USA and Canada, where vitamin D milk fortification is mandatory and others like Japan and North-European countries despite high fish consumption. From 1 to 5 years of age and during adolescence, a winter vitamin D3 supplementation is necessary with 80.000 or 100.000 IU periodic loads every 3 months i.e. in November and February. In cases of an underlying risk, i.e. insufficient vitamin D photosynthesis in summertime (dark skin, wearing heavily skin-covering clothes, or several skin diseases), or digestive, renal or nutritional pathologies, use of some drugs, loading dose of 80.000 or 100.000 IU, every 3 months should be administered over the year.

Lightwood syndrome revisited with a novel mutation in CYP24 and vitamin D supplement recommendations.

A novel mutation in CYP24A1 provides insight into idiopathic infantile hypercalcemia. In this report of 3 brothers, in twins supplemented with vitamin D (1900 IU/d), only the twin homozygous for CYP24A1 exhibited idiopathic infantile hypercalcemia. A subsequently affected younger brother given vitamin D 400 IU/d was not hypercalcemic.