Warning issued for some women on vitamin D, calcium
Healthy post-menopausal women should not take low-dose vitamin D and calcium supplements in hopes of protecting their bones, a panel of government advisers said in a new recommendation.
The supplements don't work for that purpose, at least when taken at the relatively low daily doses that have been most thoroughly studied, said the U.S. Preventive Services Task Force. The advice, published on Monday in the Annals of Internal Medicine, covers daily doses up to 400 international units (IU) of vitamin D and up to 1,000 milligrams of calcium.
The recommendation is an official vote of no confidence in a very popular supplement combination. Though it closely tracks a draft released months ago and is based on widely reported studies, it may be a shock to many consumers. More than half of women older than 60 take the supplements, according to the task force.
The recommendation is likely to spawn confusion because it doesn't cover younger women, men or higher doses. The task force says it has inadequate evidence on all those issues. It also continues to study whether vitamin D has any role in preventing cancer. And it is standing by a previous recommendation that people who are older than 65 and at high risk for falls — a big group of people — should take vitamin D supplements.
“We know that vitamin D and calcium are essential to bone health,” said task force member Jessica Herzstein, a public-health specialist who is global medical director at Air Products in Allentown. But studies including the Women's Health Initiative show that low-dose supplements don't prevent fractures in healthy older women, the task force said. Research suggests that about one in 273 women taking the supplements will develop kidney stones. It's a small risk but worth considering, Herzstein said.
The best advice is for women to talk to their doctors about their risks for fragile bones and fractures, and all the ways they can prevent them, including diets high in calcium and vitamin D, exercise and prudent sun exposure, which helps the body produce vitamin D, Herzstein said.
But some women who talk with their doctors will find waning enthusiasm for the supplements, said Clifford Rosen, a senior scientist at Maine Medical Center Research Institute and former president of the American Society for Bone and Mineral Research. There's a growing consensus that “most people are doing very well in the United States in terms of their vitamin and mineral intake and they don't need supplements,” he said. There's also growing concern about risks.