The Benefits of Vitamin D

Vitamin D's most important function is to regulate the body's absorption and use of calcium and phosphorus, thereby making this vitamin essential for bone and tooth formation and strength. Since calcium is also necessary for muscle contraction and sending messages along the nerves, vitamin D is important to these areas, too.

Vitamin D and Osteoporosis
Osteoporosis is a progressive condition characterized by decreased bone density. That is, the mineral content of the bones is diminished, making them brittle, weak, and more likely to break. The condition is most common in women who have gone through menopause, but older men get osteoporosis, too, though it's generally less severe. Although most people think of calcium as being the the anti-osteoporosis nutrient, vitamin D's role is also essential.

Both fractures in older people are increasingly recognized to be a result of osteoporosis. And for more than 20 years, experts have known that vitamin D deficiency is associated with an increased risk of hip fracture. A recent study conducted at Brigham and Women's Hospital in Boston found that half of the women with hip fractures were deficient in vitamin D.

In some regions of the United States, where sunshine is less abundant and weaker during the winter, researchers have documented measurable loss of bone mineral density in the hips and spines of older people. This is especially troublesome for those who may not be getting adequate amounts of vitamin D from milk products. Researchers from Tufts University found that daily supplements of 500 milligrams of calcium plus 700 IU of vitamin D, taken for three years, decreased the risk bone fractures in older men and women by 50 percent. A previous study with the same supplements taken over a two-year period resulted in a 43 percent reduction of hop fractures in older women. Experts believe that the main way vitamin D contributes to bone density is by increasing calcium absorption in the small intestine. This ensures an adequate level of calcium in the blood, which can then be deposited in the bone.