Vitamin D is produced when skin is exposed to sunlight. This vitamin is crucial for bone health as it facilitates calcium absorption, thereby preventing conditions like osteoporosis. Sunlight triggers the conversion of 7-dehydrocholesterol in the skin to vitamin D3, which is then processed by the liver and kidneys into its active form. Adequate levels of vitamin D are essential for overall health and play a role in immune function, potentially reducing the risk of chronic diseases. Supplementation may be necessary in regions with limited sunlight exposure.