Vitamin D and Calcium Together May Reduce Fracture Risk for Elderly
Vitamin D and Supplements for Elderly
Elderly people who are frail and at risk for bone fractures may be helped somewhat by giving them both vitamin D and calcium, according to the results of a new review of previous studies.
The combination marginally reduces the risk of some types of bone fractures, but the effect appears only in those who live in nursing homes or other institutions.
"Frail older people confined to institutions appear to experience a reduction in hip and other non-vertebral fractures if given vitamin D with calcium supplements," writes Alison Avenell, M.D., of the University of Aberdeen, Scotland, and her colleagues. Vitamin D alone and calcium alone does not appear to have any effect on reducing the risk of fracture.
The review appears in the current issue of The Cochrane Library, which is published by The Cochrane Collaboration, an international organization that evaluates medical research.
These reviews draw their conclusions about medical practice that are based on evidence from several clinical studies, after the reviewers consider both the content and quality of medical studies on a given topic.
In a review of 38 randomized or quasi-randomized trials, the risk of fractures of the hip and other non-spinal bones was reduced slightly if vitamin D and calcium were given. However, the risk of spinal fractures did not appear to be reduced.
These findings differ from an evidence review in last May's Journal of the American Medical Association that suggested a benefit from vitamin D alone for hip or non-spinal fractures. But Avenell and colleagues say their conclusion showing a benefit only from a combination of vitamin D and calcium is based on a much larger number of patients and on the fact that in some cases, the other study included trials of vitamin D with and without calcium.
Synthetic vitamin D in drugs such as calcitriol (Rocaltrol) did not appear to have any advantage in preventing bone fracture and may be more likely to cause adverse reactions than natural vitamin D, the review reports.
Although hip and arm fractures are painful and immediately debilitating, fractures of the vertebrae may never be diagnosed. They can cause serious back pain and lead to the characteristic bent-over spine seen in people with severe osteoporosis.
Studies have shown that one-third to one-half of all women in Europe and North American over the age of 75 have vertebral fractures. The findings of this review apply only to patients who live in nursing homes or residential care facilities. "It remains unclear whether the results can be generalized to other health and social care systems," the authors write.
Osteoporosis -- the thinning and weakening of bones -- in the elderly is a serious problem. While it affects women primarily, elderly men are also at risk. In the United States, the lifetime risk of breaking a hip is 17.5 percent for women and 6 percent for men. The risk of vertebral fractures is 15.6 percent for women and 5 percent for men and for breaking the wrist or forearm, it is 16 percent for a women and 2.5 percent for men.
Bones are continuously in a state of being built up and broken down. Vitamin D aids the body in keeping these two actions in balance so that bone mass is not depleted. Calcium supplements also protect bone mass.
Most vitamin D is synthesized in the body when it is exposed to sunlight, but vitamin D supplements are inexpensive and do not have to be given continuously. In contrast, synthetic vitamin D is expensive and may be more likely to have adverse effects such as excessive calcium in the blood.
Eleven of the 38 trials that were analyzed for the review were large, with from 600 to 9,000 patients enrolled. Six trials had between 150 and 500 patients enrolled.
The remaining 21 trials were smaller, with fewer than 150 participants total. Some of the trials compared the effects of vitamin D alone to placebo or to no treatment, some compared vitamin D and calcium to calcium alone, and some compared vitamin D to calcium.
Most effective treatments for osteoporosis involve taking preventive measures years before bones are weakened to the point where fractures occur, according to Avenell and her colleagues. Other factors also affect the incidence of broken bones, including better attention to the prevention of falls in the elderly.