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 JAMA on Tuesday took a fresh look at this issue by analyzing 33 randomized clinical trials involving 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 conclusion was clear that vitamin D and calcium supplements do not seem to be warranted to prevent bone breaks or hip fractures in the elderly 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 this practice 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.” She said this week that bone health involves many different aspects of eating and activity.
“Bone preservation throughout life requires eating healthfully, engaging in weight-bearing activity, avoiding excessive alcohol, and not smoking – good advice for everyone,” Nestle said.
Vitamin D is not a vitamin but a hormone which is produced in reaction to sunlight and seems to have many different roles in the body related to the bones, cancer, heart disease, diabetes, immune function and health.
The new study did not look at the benefits or risks of supplements on other conditions, but previous studies have suggested that vitamin D can lower risks for diabetes and certain cancers. However, an April 2017 study in JAMA Cardiology found that high monthly doses of vitamin D supplements didn’t seem to do much to help with cardiovascular disease.
The JAMA study, conducted by Jia-Guo Zhao of Tianjin Hospital in China, was focused solely on older adults who lived in the general community and did not include those in nursing homes, hospitals and other facilities. One other limitation of the study is that some of the trials included in the analysis did not test baseline vitamin D blood concentration in all participants.