Vitamin D and bone health

Metabolic bone diseases bear an immense economic burden as per population health surveys, and the role of vitamin D has been extensively studied. Ultraviolet-B (UV-B) rays produce vitamin D3 in the skin, which is subsequently metabolized in the liver and kidney to form 1,25-dihydroxyvitamin D. This active metabolite causes absorption of calcium from the intestines and maintains a balance between calcium/phosphorus to ensure adequate bone mineralization. Multiple environmental and medical factors can affect the production of active vitamin D. Nutritional supplementation is necessary to overcome insufficiency. High-risk populations must be screened for vitamin D deficiency by testing for 25-hydroxyvitamin D levels. A minimum daily requirement of 1000mg/day of calcium and at least 600 IU/day of vitamin D is essential to preserve bone integrity. Higher doses are preferred for elderly, pregnant, or breastfeeding women. Different formulations of vitamin D are available, but caution must be exercised because overuse may result in hypervitaminosis D.