Cholecalciferol can be produced industrially by the action of ultraviolet light on 7-dehydrocholesterol. Vitamin D that is formed in the skin from ultraviolet radiation is absorbed into the circulatory system.
Vitamin D is stored in the liver where it is metabolized into calcidiol.
Further metabolic reactions take place in the kidneys where it is converted to calcitriol and then absorbed into the blood where it is stored in fat and muscle. Calcitriol is a hormone that helps regulate the body's calcium needs. It aids in the absorption and utilization of calcium and phosphorus. They are two minerals essential for healthy development of bones and teeth. Vitamin D is valuable for maintaining normal blood clotting, a stable nervous system, normal heart function, and proper functioning of muscles, blood clotting, cell growth, and energy utilization.