Older women are advised against taking supplements to prevent fractures
■ U.S. Preventive Services Task Force says more research is needed to weigh the risks and benefits of vitamin D and calcium supplements in other populations.
Physicians should advise postmenopausal women against taking low doses of vitamin D and calcium supplements to prevent fractures, says the U.S. Preventive Services Task Force.
Such supplements often are recommended for older women to help strengthen bones, but evidence shows that the risks outweigh the benefits, says a task force draft recommendation, which is open for public comment through July 10.
Specifically, the group advises against postmenopausal women taking daily supplements of 400 international units or less of vitamin D3 and 1,000 milligrams of calcium to prevent fractures.
“The evidence is clear that [the dosage] is really not effective and is associated with a small but measurable harm,” said Kirsten Bibbins-Domingo, MD, PhD, task force member and associate professor of medicine at University of California, San Francisco.
About 1.5 million osteoporosis-related fractures occur in the U.S. each year, said the report (link).
The Centers for Disease Control and Prevention estimates that 4.5 million women 50 and older, or 10%, have osteoporosis of the hip. And nearly half of all women older than 50 will have an osteoporosis-related fracture.
Research has shown that low doses of vitamin D and calcium supplements have no effect in preventing fractures in postmenopausal women. Meanwhile, there is evidence that the supplements increase the risk of renal stones in those individuals. A seven-year, randomized trial that was part of the Women’s Health Initiative found that one in every 273 women taking the supplements had a urinary tract stone, the report said.
“Our goal, as with everything that the preventive task force does, is to really synthesize the available evidence,” Dr. Bibbins-Domingo said.
The recommendation is not a surprise, said Andrew Ruthberg, MD, assistant professor of medicine in the division of rheumatology at Rush University Medical Center in Chicago. Many physicians already recommend supplements less to patients.
“This is part of an evolving process where we’re seeing more and more negative thoughts about using supplemental calcium, in particular, and, to a lesser extent, vitamin D,” Dr. Ruthberg said. “This will encourage us to use dietary sources of nutrients rather than manufactured supplements.”
Dr. Bibbins-Domingo stressed that the recommendation is intended for otherwise healthy women, and that vitamin D and calcium are part of a healthy diet. There isn’t enough evidence to determine whether the supplements should be recommended to prevent fractures in men and premenopausal women, the report said. The risks versus benefits of larger doses also is unknown.
In a previous recommendation, the task force found that vitamin D supplements help prevent falls in adults 65 and older who are living in nursing homes or other assisted-living facilities.