[Vitamin D revisited: a cornerstone of health?].

There is a recent renewed interest in vitamin D metabolism and pathophysiology, due to its recent description as a hormone with a positive impact on global health rather than a strictly bone hormone: vitamin D could be a protective factor against infection, autoimmunity, cardiovascular morbidity, and cancer. By contrast, vitamin D deficiency appears to be increasingly frequent worldwide. We propose a review of these new aspects of vitamin D metabolism, with a focus on vitamin D status in a local pediatric cohort. There is an urgent need for revisiting current guidelines on vitamin D supplementation and for closely monitoring serum vitamin D in children with chronic diseases, i.e., at greater risk of cardiovascular impairment, bone morbidity, infectious disease, and acute inflammation.