Healthy Older Women Advised Against Taking Calcium
Criticism about the USPSTF guidelines comes from a range of perspectives.
The Council for Responsible Nutrition, a trade association representing the dietary supplement industry, criticized the USPSTF for relying too heavily on data from the Women's Health Initiative (WHI), a study that showed little to no effect on fracture rates in the more than 35,000 postmenopausal women in the trial. They also said that the task force ignored a WHI study out this year that showed a notable reduction in fracture among women who adhered to prescribed doses of calcium and vitamin D.
Some experts prefer a report released by the Institute of Medicine (IOM), a nonprofit organization that gives expert, evidence-based advice on public health issues to policy makers and health professionals.
"That took a very in-depth and I would say a very broad look at the vitamin D and calcium question," said Dr. Sundeep Khosla, a past president of the American Society for Bone and Mineral Research and an endocrinologist and research scientist at the Mayo Clinic. The IOM recommended that most adults get 1,000 mg of calcium, and that women older than 50 and men older than 70 get 1,200 mg of calcium, according to Khosla.
Khosla said the IOM and the USPSTF were each "looking at different parts of the elephant." He said that the USPSTF was focused just on what it took to prevent fracture, ignoring the fact that among healthy people who haven't yet had a break, it would be difficult to detect whether supplements are effective.
"With the IOM taking the physiological perspective, their work might be considered more sensitive [more able to pick up potential benefits or risks]," he said
Marion Nestle, a professor of nutrition, food studies and public health at New York University, co-wrote a journal editorial suggesting that statements from the task force are unlikely to settle the ongoing debate about the use of vitamin D and calcium. "The task force looks at one or two nutrients and one condition at a time, but that's not how people eat or live," she said.
Yet Nestle said she thinks the guidelines suggest reasonable approaches to prevention. "Clinicians ought to be advising healthy diets, plenty of activity and at least 15 minutes a day of sun exposure," she said.
Dr. Margery Gass, executive director of the North American Menopause Society, helped create clinical guidelines on osteoporosis for the American College of Obstetricians and Gynecologists published last year. Gass said she thinks the sheer number of guidelines being disseminated from a variety of different groups is "likely to stir up a little confusion and frustration" among clinicians and the public. But she added that the core message of the USPSTF guidelines is actually simple. "The good thing is that healthy people who do eat a variety of foods may not need to feel compelled to take supplements," she said.