Vitamin D and calcium supplements have long been recommended to help prevent bone fractures, but the benefits for healthy, older women are overstated and may even be detrimental to their health, according to a new study published in the Annals of Internal Medicine.
The U.S. Preventative Services Task Force says there’s not enough evidence to make an accurate assessment on whether Vitamin D and calcium supplements lower the risk of bone fractures. The panel did find the supplements raise the risk of developing kidney stones for healthy women over 60.
“In premenopausal women and in men, there is inadequate evidence to determine the effect of combined vitamin D and calcium supplementation on the incidence of fractures,” writes study author Dr. Virginia Moyer.
About 1.5 million Americans suffer fractures caused by brittle bones each year. About half of all older women will end up with a break that’s linked to the bone-weakening disease osteoporosis.
That’s a major concern, wrote Moyer, because fractures are associated with chronic pain, disability, loss of independence and decreased quality of life. And hip fractures significantly increase the risk of illness and death.
Physicians currently recommend Vitamin D and calcium supplements for older women to prevent fractures. About 56% of women 60 years and older take vitamin D and 60% take a supplement containing calcium.
The task force continues to recommend that women older than 65 be screened for osteoporosis, along with younger women who have a high risk of broken bones. But the panel recommended against daily doses of Vitamin D of less than 400 IU (international units), and calcium in daily doses of less than 1,000 milligrams for post-menopausal women.
Doses of that level, according to the task force, have “no effect on the incidence of fractures.”
The recommendations do not apply to people who already have a diagnosis of osteoporosis, a history of fractures, documented Vitamin D deficiency or are living in an assisted-living community. In those instances, the panel recommends vitamin D supplementation of at least 800 IU to strengthen muscles and help with balance.
“Vitamin D, of course, is not a vitamin in the usual sense. It is a hormone produced in response to the action of sunlight on skin. Like other hormones, vitamin D has multiple roles in the body, not all of them well-understood,” said Marion Nestle, a nutrition researcher from New York University in a commentary published along with the task force recommendations.
“Vitamin D supplementation, therefore, must be considered a form of hormone replacement therapy. As such, it raises all of the questions about efficacy, dose, and side effects currently asked of such therapies.”
Nestle added that although further research is needed before the debate over the effectiveness of Vitamin D and calcium supplements is resolved, she applauded the study for the cautious, evidence-based advice she hopes will “encourage clinicians to think carefully before advising calcium and vitamin D supplementation for healthy individuals.”
But not everybody agreed with the conclusions of the study.
In a statement, the trade group for the dietary supplement industry, the Council for Responsible Nutrition, said the recommendations failed to recognize the well-established role of calcium and vitamin D in maintaining bone health.
“If these recommendations are taken to heart, or misconstrued as general recommendations against calcium and vitamin D, consumers could be compromising their bone health and missing out on important other benefits from these nutrients.”
According to the Nutrition Business Journal, sales of vitamin D supplements rose from $42 million in 2002 to $605 million in 2011.