[Vitamin D supplementation: why and how?].

In addition to osteomalacia and rickets which are the main classical consequences of severe vitamin D deficiency, osteoporosis and extra skeletal manifestations were more recently linked to decreased vitamin D levels. Painful myopathy, cancer, autoimmune disorders and probably cardiovascular events are also more prevalent in vitamin D deficient adults. Elderly people and pregnant women are the main groups at risk of vitamin D depletion. The recommendations of photoprotective regimen to protect against skin cancer are in part responsible for the increased prevalence of vitamin D deficiency. We here review the management of vitamin D deficiency and the current recommendations for vitamin D repletion in specific groups of subjects with overt vitamin D depletion or at risk to be deficient.