Calcium, vitamin D may not protect against fractures

One of the most contentious questions in nutrition science over the past decade has been whether older adults should be taking supplemental vitamin D and calcium. As the world’s population ages and broken bones and fractures become even more of a public health concern, with huge social and economic consequences, researchers have been trying to make sense of conflicting studies on the association between supplements and fracture risk.

A study published in the Journal of the American Medical Association on Tuesday took a fresh look at this issue by analyzing 33 randomized clinical trials involving a total of more than 50,000 adults over the age of 50. Each of these previous research papers involved comparing calcium, vitamin D or both with a placebo or no treatment. The analysis, conducted by Jia-Guo Zhao of Tianjin Hospital in China, was focused on older adults who live in the general community and did not include those in nursing homes, hospitals and other facilities.

The conclusion was clear: Vitamin D and calcium supplements do not seem to be warranted to prevent bone breaks or hip fractures in those adults. Such supplements had no clear benefit regardless of dose, the gender of the patient, history of fractures or the amount of calcium in the diet.

The U.S. Preventive Services Task Force, an influential federal advisory body, has raised questions about these supplements since 2013, when it issued recommendations saying evidence to support the benefit of the supplements in older adults without osteoporosis or vitamin D deficiency was “insufficient.”

Marion Nestle, a professor emerita of food sciences and nutrition at New York University, wrote in an opinion piece at that time that the UPSTF’s statement should caution clinicians “to think carefully before advising calcium and vitamin D supplementation for healthy individuals.”

Vitamin D is not a vitamin but a hormone that is produced in reaction to sunlight and seems to have many different roles in the body related to bones, cancer, heart disease, diabetes, immune function and reproductive health.

Daniel Fabricant, president of the Natural Products Association, which represents manufacturers and retailers of dietary supplements, said the study draws its conclusions with “too broad of a brush.” He said it focuses on the healthiest segment of the population by looking at people who are able to live at home.

“There is a lot missing,” Fabricant said. “People with prior breaks or family incidence of osteoporosis may still need vitamin D.”