Friday, January 5, 2018

Seniors Don’t Need Calcium, Vitamin D Supplements

Seniors are wasting their time and money taking calcium and vitamin D supplements to ward off the brittle bones of old age, a new review concludes.

It turns out there’s little evidence supplements protect against hip fractures and other broken bones in older folks, according to data gathered from dozens of clinical trials.

“The routine use of these supplements is unnecessary in community-dwelling older people,” said lead researcher Dr. Jia-Guo Zhao, an orthopedic surgeon with Tianjin Hospital in China. “I think that it is time to stop taking calcium and vitamin D supplements.”

Zhao and his colleagues combed through medical literature to find clinical trials that previously tested the usefulness of calcium and Vitamin D supplements. They wound up with data from 33 different clinical trials involving more than 51,000 participants, all of whom were older than 50 and living independently.

Most of the clinical trials took place in the United States, the United Kingdom, New Zealand and Australia Zhao said. The dosage of the supplements varied between the clinical trials, as did the frequency at which they were taken.

The pooled data revealed no significant association between calcium or vitamin D supplements and a person’s risk of hip fracture or other broken bones, compared with people who received placebos or no treatment at all.

Potential dietary sources of these nutrients prove one of the weaknesses of the evidence review, argued Dr. Daniel Smith, an assistant professor of orthopedics at the Icahn School of Medicine at Mount Sinai in New York City. “While this study addresses concerns regarding calcium and vitamin D supplementation, it fails to address or even consider whether the patients in question are obtaining either adequate calcium and vitamin D intake in their diets or sunlight exposure, obviating the need for supplementation,” Smith said.

The evidence review also included a large amount of data from the Women’s Health Initiative, a federally funded study of aging U.S. women. “Unfortunately, the WHI data has been widely acknowledged as having limitations of its own having to do with subjects not taking the supplements as directed by the protocol, as well as those who took calcium and vitamin D supplements on their own, outside the protocol, before and during the study,” said Andrea Wong, vice president of scientific and regulatory affairs with the Council for Responsible Nutrition. Inclusion of the WHI might have skewed the overall results of the review Wong argued.

The new analysis was published Dec. 16 in the Journal of the American Medical Association.

My Take:
This is a prime example of a poor study that failed to meet peer review guidelines but was published anyway, in JAMA of all places. As you probably noted, this study was picked-up by the major news media last week. Unfortunately, television did not report the numerous flaws in the study.

Clinically, I find that the source of calcium and when it is taken are the two most important aspects of proper supplementation. I also believe that varying the source of calcium, to mimic dietary calcium in vital. Finally, calcium supplementation is just that, a supplement to dietary calcium, not a replacement.

The other issue ignored by all reporting sources on this study is the other uses of vitamin D and calcium in the body. Yes, almost 99% of calcium is stored in bone. Bone is a repository for calcium where it can be removed and replaced as need to buffer the pH of the blood stream. It is the protein in bone, mostly in the form of collagen, that makes bone strong.

Vitamin D is really a hormone, not a vitamin. We know about its action to increase calcium absorption but it also plays a major role in the immune system and genetic transcription. Vitamin D is thought to be a key player in preventing many cancers and autoimmune disease.

The Bottom Line:
Don’t believe this flawed study. I frequently find my patients have low vitamin D levels in the blood, despite living in sunny South Florida. All women need to supplement calcium. Women need at least 1000mg per day and obtain about 500mg at best from a healthy diet. Men also can benefit from calcium supplementation, especially if they are exercising daily.

Source: December 26, 2017 National Institutes of Health

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