In defense of D

In defense of D

CRN responds to two systematic reviews and a guest editorial published online in the British Medical Journal that question the benefits of vitamin D supplements.

In response to two systematic reviews/meta-analyses and a guest editorial published online in the British Medical Journal, the Council for Responsible Nutrition (CRN), the leading trade association representing the dietary supplement industry, issued the following statement:

Statement by Duffy MacKay, N.D., senior vice president, scientific and regulatory affairs, CRN: 

“The body of scientific research demonstrating beneficial results for vitamin D has grown in recent years. We know that vitamin D is a critical conduit for multiple physiological bodily functions, as well as a tool for helping calcium absorption, which is essential to building strong bones. Now, a new systematic review and meta-analysis finds vitamin D supplementation may also play a significant role in reducing the risk of mortality, particularly in older adults. We agree with the study authors that further research should be done to identify an optimal dose and duration for this encouraging finding; but there is enough positive research currently to indicate that people should be supplementing with vitamin D for a variety of positive health outcomes.

“Although the second umbrella review in this week’s issue, by Theodoratou et al., recognized ‘probable’ and ‘suggestive’—but not ‘highly convincing of a clear role’—associations for vitamin D and various conditions and diseases, it also indicated that further research is needed to draw firmer conclusions. There are very few things that provide clear cut scientific evidence when you’re talking about chronic disease, and if adding a simple vitamin D supplement might provide even probable benefits in this area-as one of a host of healthy habits—we should encourage that step. 

“As we’ve seen in other studies, there is something about certain diseases that seems to either be depleting the body of normal levels of vitamin D, or the low levels are contributing to the disease. In either case, where patients present with insufficient levels of this critical nutrient, supplementing with vitamin D makes sense—whether it actually slows the progression of the disease or rather helps to replace the depleted nutrient levels being caused by the disease.

“The importance of vitamin D continues to be recognized by the scientific, medical and even regulatory communities. In its latest review of vitamin D, the Institute of Medicine (a scientific advisory board to the government) raised the recommended levels for vitamin D. Just last month, in a recently released proposed rule from the U.S. Food & Drug Administration on nutrition and supplements facts labels, the agency identified vitamin D as a ‘nutrient of public health significance,’ advising that vitamin D content be listed on food labels.

“Rather than following the recommendations from the guest editorial authors Welsh and Sattar to stop testing blood levels for vitamin D for ‘asymptomatic patients outside of bone disease related conditions,’ we recommend this be handled on a case-by-case basis between patient and doctor.  No one should consider vitamin D to be a magic bullet, and in fact, we know of no research that demonstrates that patients may gain ‘false reassurance’ of protection by taking a vitamin D supplement.

“It is important for patients and their healthcare practitioners to work together to ensure they are getting the recommended amount of vitamin D—which is not easily obtainable through food alone, and may not be safely available through the sun, making vitamin D supplements a safe and beneficial alternative.”


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