Insuffisance Et Déficit En Vitamine D : Épidémiologie, Indications Du Dosage, Prévention Et Traitement

Vitamin D has been traditionally considered as important for skeletal health. However, during the past decade, numerous research findings have revealed that vitamin D may have beneficial effects on extraskeletal tissues as well. Vitamin D deficiency is now recognized as a worldwide issue. The prevalence of vitamin D deficiency or insufficiency depends on the threshold used to define vitamin D deficiency or insufficiency. However, whatever the threshold (20, 30 or 40 ng/mL), the prevalence is high in France as elsewhere. Vitamin D status is now based on the measurement of 25-hydroxyvitamin D [25(OH)D] concentration. This assay does not seem justified in most situations encountered in clinical practice, and its overprescription generates a significant cost to public health. This is why Official Clinical Societies try to define: (a) target populations for which a determination is required (every situation in which the therapeutic goal requires an optimal serum 25(OH)D level for an appropriate medical care) and which require specific treatment; (b) target populations for which the risk of deficit is important (due to insufficient daily intake) and may benefit from preventive pharmaceutical supplementation without prior testing (infants, pregnant women, patients over 65...).