06/13/2012 02:48 pm ET Updated Jun 14, 2012

Vitamin D Doesn't Prevent Osteoporosis In Healthy Women, Task Force Says

Reversing decades of commonly accepted medical advice, the U.S. Preventive Services Task Force released a recommendation on Tuesday that healthy post-menopausal women should no longer take vitamin D and calcium supplements to protect against osteoporosis-related bone fractures.

"There is sufficient evidence to say they do not prevent fractures," task force member Dr. Kirsten Bibbins-Domingo, an associate professor of medicine at the University of California in San Francisco, told the New York Times of the typically recommended cocktail of 400 IU of vitamin D and 1,000 mg of calcium.

The task force, comprised of medical professionals who have been appointed by the U.S. Department of Health and Human Services, analyzed data from 137 clinical studies -- 19 of them randomized and controlled -- that investigated vitamin D's role in osteoporosis-related fracture for postmenopausal women; fracture for premenopausal women and for men; and cancer prevention for breast, prostate and colorectal cancer.

The task force found insufficient evidence to support use of the vitamins for premenopausal women and for men, as well as to support the claim that the vitamins play a role in preventing cancer.

But the strongest evidence related to fracture among healthy postmenopausal women: There wasn't just insufficient evidence that the recommended dose of vitamins helped, there was sufficient evidence that they did not. The only people who benefitted from vitamin D and calcium, in terms of preventing fractures, were nursing home and assisted living facility residents, according to WebMD.

Still, some doctors believe that vitamin D and calcium may be useful to help prevent bone fracture, though at higher doses. "It's been known for some time that that is too low of a dose," Dr. Silvina Lewis, who works at the Osteoporosis Center at the University of Miami Miller School of Medicine in Florida, told Reuters.

CORRECTION: The headline has been amended to reflect the task force's specific recommendation more closely.