Vitamin D: Keeping Bones Strong

Vitamin D helps the body absorb calcium and phosphorus from the intestine. Calcium and phosphorus are two of the main components of bone. Thus, vitamin D is necessary for the formation of normal bones. Good sources of vitamin D are milk (which is fortified with vitamin D), green vegetables, egg yolks, fish, and fortified cereals. Also, vitamin D is formed when the skin is exposed to sunlight.

Vitamin D deficiency may develop because not enough vitamin D is consumed in foods. For example, many older people do not drink a lot of milk. Vitamin D deficiency may also develop because the skin is not exposed to enough sunlight. For example, older people tend to spend less time outdoors. Some older people are confined to their bed and do not go outside. Also, in older people, less vitamin D is formed when the skin is exposed to sunlight. Disorders or drugs that interfere with the body's use of vitamin D can cause a deficiency. Examples are digestive tract, liver, and kidney disorders and the anticonvulsants phenytoin and phenobarbital.

Treatment of vitamin D deficiency depends on the cause. But it almost always includes vitamin D supplements.