Postmenopausal women shouldn’t take low-dose supplements of vitamin D and calcium in hopes of preventing broken bones, a government panel recommended on Tuesday.
The U.S. Preventive Services Task Force (USPSTF) based its draft recommendation — available for public comment until July 10 — on a recent review of the latest research, which found that taking daily supplements of 400 IU of vitamin D combined with 1,000 mg of calcium did little to reduce the risk of bone fracture in healthy postmenopausal women (the data did find, however, that supplements helped prevent bone breaks in women living in nursing homes or assisted-living facilities). The evidence also suggested that low-dose supplementation slightly increased the risk of kidney stones, and therefore confers “no net benefit” for the prevention of fractures.
The panel said there wasn’t adequate evidence on the benefits of higher daily doses of vitamin D and calcium to make a recommendation either way. It also found insufficient evidence to determine whether the supplements had any effect on users’ cancer risk.
That’s not to say that vitamin D and calcium aren’t necessary for good health overall. The new recommendations apply only to postmenopausal women taking low-dose supplements to prevent fractures. According to guidelines from the Institute of Medicine, people should be getting 600-800 IU of vitamin D daily and 700-1,300 mg of calcium, depending on age and gender. Most people get enough of both, either through diet — milk and yogurt, for instance, are rich in calcium and fortified with vitamin D — or supplements. People also get vitamin D through sun exposure.
Some experts agreed with the task force’s conclusion. Reuters reported:
Dr. Silvina Levis of the Osteoporosis Center at the University of Miami Miller School of Medicine in Florida said she’s happy with the recommendation against the low-dose supplements.
“It’s been known for some time that that is too low of a dose,” she said. But she added that she still believes there is a benefit to higher doses.
Others found the USPSTF recommendation to be too general, and advised women to talk to their doctors about their individual supplement needs based on ethnicity and geography. USA Today reported:
The studies analyzed by the government panel have important limitations, says Jen Sacheck, an assistant professor and researcher in the antioxidants research laboratory at Tufts University in Boston. The research largely involved white people and no accommodation was made for how nutritional needs may vary by where a person lives, she says.
“It’s a more complex picture than they’re painting,” she says. “If you live in New England there are many months of the year when you’re not getting adequate amounts of vitamin D from the sun. I check blood levels of young and older people and find them to be low in New England.”
Although the government panel concluded that daily low-dose supplements don’t have much of a protective effect, experts point out that postmenopausal women at risk of fracture can try other widely beneficial lifestyle changes: improving their diet and increasing weight-bearing exercise.