March 13, 2013
Task Force Recommends Against Common Supplements for Healthy Americans
Rockville, MD—How should pharmacists respond when healthy older women ask whether vitamin D and calcium supplements will improve their health and help prevent fractures?
A new United States Preventive Services Task Force report provides a possible answer. The panel recommends against daily supplementation with doses of vitamin D less than or equal to 400 IU and calcium less than or equal to 1,000 mg for the primary prevention of fractures in postmenopausal women living in the community setting.
In the recommendations, published recently in the Annals of Internal Medicine, the authors caution that “these recommendations apply to non-institutionalized or community-dwelling asymptomatic adults without a history of fractures. This recommendation does not apply to the treatment of persons with osteoporosis or vitamin D deficiency.”
The task force said it found insufficient evidence to assess the benefits and harms of daily supplementation with higher doses in this population or to recommend for or against daily vitamin D and calcium supplementation to prevent fractures in premenopausal women or in men.
The article points out the dilemma in recommending for or against supplementation. One half of all postmenopausal women will have an osteoporosis-related fracture in their lifetime, and those fractures (especially when the hip is involved) are not only associated with chronic pain and disability, but increased mortality. On the other hand, vitamin D and calcium supplements are inexpensive and readily available without a prescription.
To develop the recommendations, the task force commissioned two systematic evidence reviews and a meta-analysis on vitamin D supplementation with or without calcium. Based on the evidence, researchers concluded with “moderate certainty” that taking daily supplements of vitamin D less than or equal to 400 IU and calcium less than or equal to 1,000 mg has no overall benefit for the primary prevention of fractures. Furthermore, according to the researchers, it increases the incidence of kidney stones.
The recommendations are unlikely to be the final answer on the issue, however, according to a commentary that accompanied the article.
Marion Nestle, MPH, PhD, of New York University, and Malden C. Nesheim, PhD, of Cornell University, write that the task force “plunges headlong into ongoing debates about whether healthy adults—those who show no signs of vitamin D deficiency or osteoporosis—should be advised to take combined supplements of calcium and vitamin D to prevent bone fractures and, if so, at what level.”
“While we wait for the results of further research, the USPSTF’s cautious, evidence-based advice should encourage clinicians to think carefully before advising calcium and vitamin D supplementation for healthy individuals,” according to the editorial.
Suggesting that the report includes “terse statements unlikely to settle the debates,” the commentators write that the task force’s recommendations “depend on hard end points—fractures—rather than on blood levels of 25-hydroxyvitamin D, at best an indirect measure of vitamin D adequacy.” That perspective, they note, results in the finding that, “In the absence of compelling evidence for benefit, taking supplements is not worth any risk, however small.”
The editorial points out that other groups, such as the Endocrine Society, offer different recommendations. The Endocrine Society, for example, uses 30 ng/mL of 25-hydroxyvitamin D as the target level for maximum benefits, and, by that measure, most adults in the U.S. require daily supplements of 1,500 to 2,000 IU.
Nestle and Nesheim write that they hope future USPSTF recommendations “keep in mind the value of making a single recommendation about vitamin D and calcium supplementation that will encompass all potential benefits and risks. Multiple recommendations by condition confuse practitioners and the public.”
The task force previously recommended that, for fracture prevention, women age 65 or older and younger women at high risk for fracture be screened for osteoporosis. Vitamin D supplementation is recommended to prevent falls in community-dwelling adults age 65 and older who are at increased risk for falls.
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