[Prevention of child and adolescent vitamin D deficiency. II. Validation of a decision-making abacus based on sun exposure and vitamin D intakes].

Objectives: Rickets can still be observed among children and adolescents living in Europe, and a significant proportion of healthy children and adolescents presents serum 25-hydroxyvitamin D (25-(OH)D) values below the threshold indicating an insufficient vitamin D status. We have previously proposed detecting at risk individuals with a decision-making abacus based on questionnaires assessing calcium and vitamin D intakes and vitamin D production via sun exposure.

Methods: We tested the validity of this detection by receiver operating characteristic (ROC) analysis, using, as the main outcome measure, the serum 25-(OH)D values measured at the time of questionnaires presentation.

[Vitamin D and pubertal maturation. Value and tolerance of vitamin D supplementation during the winter season].

Background: In France, several cases of vitamin D-deficiency rickets among adolescents have been reported, but no prophylaxis measure has been systematically recommended at this age. The aim of this study was to measure 25-hydroxyvitamin D (25-(OH)D) levels and to search for biological signs of vitamin D deficiency during adolescence. Moreover, the effects of a unique oral dose of 100,000 IU of vitamin D3, given during the winter, were analysed.