Vitamin D status and risks of falls.




Journal of the American Geriatrics Society

Related Monographs

Consumer Data: Vitamin D Osteoporosis
Professional Data: Vitamin D Osteoporosis


Unlike the dead, brittle skeleton hanging in the high school biology lab, bone is a living, metabolically active tissue. Throughout life, bone is constantly rebuilding itself. Bone serves as a storehouse for minerals, chiefly calcium, which can be tapped to meet the body's mineral requirements. Bone is broken down through a process called "resorption," releasing its minerals into the general circulation. New bone is then formed to replace the reabsorbed bone, preventing a net loss of bone. This is called bone "remodeling." As we age, however, bone formation begins to fall behind, causing the gradual bone loss that culminates in osteoporosis.

While a certain amount of bone loss seems inevitable with the passage of time, the process is not entirely beyond our control. Dietary and lifestyle measures can, to some degree, help maintain bone health. Poor nutrition and other health habits such as smoking, alcohol abuse, and physical inactivity contribute to bone loss. Exercise, especially through activities like walking that put pressure on the weight-bearing bones, stimulates bone remodeling. Exposure to sunlight is helpful. Vitamin D is known as the "sunshine" vitamin because it is formed in the body by the action of the sun's ultraviolet rays on the skin. Sunlight forms vitamin D in the skin, vitamin D in turn increases calcium absorption. The fat-soluble vitamin is converted in the kidneys to the hormone calcitrol, which is actually the most active form of vitamin D. The effects of this hormone are targeted at the intestines and bones.

A recent study conducted in Australia examined the serum levels of vitamin D and the risk falling among elderly women in different levels of care. Researchers gathered information on current medications, previous bone fractures, cognitive function and weight in 667 women. Serum levels of vitamin D were also recorded. After analyzing this information vitamin D deficiency was found in 144 women in low-level care and 488 in high-level care. In addition, it was discovered that a low vitamin D status was associated with an increased risk of first time falls. The authors concluded that, “A low level of serum vitamin D is an independent predictor of incident falls.”1