Vitamin D is a fat-soluble vitamin.
Unlike most vitamins, vitamin D is manufactured by the body. Ultraviolet (UV) rays from the sun alter a cholesterol-like substance in the skin, which is converted to vitamin D in the liver and kidney.
Aging: Seniors and the elderly might need 600IU to 800IU of vitamin D daily to help prevent bone loss associated with osteoporosis.
Cancer: Vitamin D might help prevent and treat colon cancer by limiting the growth of cancer cells.
Osteoporosis: Poor dietary intake of vitamin D results in reduced bone size and strength, which increases the risk of developing osteoporosis. Taking recommended amounts of vitamin D and calcium reduces osteoporosis risk.