Vitamin D and skeletal health: Practical approaches for bone health across the lifespan

Vitamin D deficiency represents a global public health concern as studies indicate that half of the world's population may be deficient in vitamin D, particularly during the winter months. Vitamin D is the primary hormone for bone mineralization in humans. It is essential for the development of the skeleton in the fetus, and further bone development in the extra-uterine environment. There is no current consensus on the recommendations for screening for vitamin D deficiency because of disagreements on the cut-off values by various medical societies, variability in testing methodologies, and a lack of clarity on the cut-off points for skeletal and extra-skeletal functions of vitamin D. As a result, confusion remains among physicians and other healthcare providers regarding when and how to screen for vitamin D, and the therapeutic serum level targets for 25-hydroxyvitamin D. This review examines the current evidence on vitamin D deficiency across the lifespan, approaches to therapy, and the ongoing lack of consensus regarding diagnosis and management of vitamin D deficiency among medical societies.