By Andrew M. Seaman
NEW YORK (Reuters Health) - Postmenopausal women shouldn't take low doses of vitamin D and calcium to prevent broken bones, a government-backed expert panel said on Tuesday.
The U.S. Preventive Services Task Force (USPSTF), which makes recommendations on a range of prevention issues, said studies of the supplements suggest they do little to prevent fractures at doses lower than 400 IU of vitamin D and 1,000 milligrams (mg) of calcium daily. But it is clear that they come with a slightly increased risk of certain side effects, including kidney stones.
The recommendations are still in draft form and will be available for public comment on the USPSTF's website for about a month before they are finalized.
For higher doses of the supplements, the evidence is still too limited to make recommendations either way, the panel found. The same is true for cancer prevention, it said.
Dr. Kirsten Bibbins-Domingo, a member of the panel and a professor at the University of California, San Francisco, said it's important for people to know that the new recommendation only applies to postmenopausal women and those taking supplements.
"We know vitamin D is very important for the body and it's important for everyone to eat a healthy diet that includes vitamin D and calcium," she said.
The Institute of Medicine, an advisory panel to the U.S. government, recommends men and women get at least 600 IU of vitamin D and at least 1,000 mg of calcium every day. The exact recommendations vary depending on age and sex.
Vitamin D and calcium supplements are often recommended for women to prevent fractures, according to the USPSTF. The supplements are widely available and are usually inexpensive.
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.
The new draft recommendations are based in part on a recent review of past research, which concluded that taking the supplements had mixed effects on cancer and broken bones (see Reuters Health report of December 19, 2011).
The review was based on 19 randomized controlled trials -- the "gold standard" of medical research -- and found supplementing a person's diet with 400 IU of vitamin D and 1,000 mg calcium may offer some protection against broken bones in the elderly. But the increased risk of kidney stones means there is "no net benefit," the panel found.
"We're fortunate that we have large studies that tell us with a moderate degree of certainty that -- in these dosages -- this supplementation is not effective in postmenopausal women with the goal of preventing fractures," said Bibbins-Domingo.
Another draft recommendation from the USPSTF out today calls for doctors to screen all women for domestic violence.
SOURCE: http://bit.ly/K7kSAx Annals of Internal Medicine, online June 12, 2012.