The classic vitamin D deficiency diseases are rickets and osteomalacia. In children, vitamin D deficiency causes rickets, which results in skeletal deformities. The kidneys, which help convert vitamin D to its active form, sometimes do not work as well when people age. Therefore, some older Americans may need vitamin D from a supplement. Homebound individuals, people living in northern latitudes such as in New England and Alaska, women who cover their body for religious reasons, and individuals working in occupations that prevent exposure to sunlight are at risk of a vitamin D deficiency.
Osteoporosis is a disease characterized by fragile bones.
It results in increased risk of bone fractures. Estrogen replacement, which limits symptoms of menopause, can help slow down the development of osteoporosis by stimulating the activity of cells that rebuild bone. Since bone loss increases the risk of fractures, vitamin D supplementation may help prevent fractures resulting from osteoporosis. Vitamin D and cancer Laboratory, animal, and epidemiologic evidence suggest that vitamin D may be protective against some cancers. Well-designed clinical trials need to be conducted to determine whether vitamin D deficiency increases cancer risk, or if an increased intake of vitamin D is protective against some cancers.