What You Need to Know: A new study, using a new technique called Mendelian randomization, provides persuasive evidence that low serum vitamin D itself increases the risk of death.
Background: Many observational studies suggest that low vitamin D levels are associated with an increased risk for disease, but it is not clear if low vitamin D is a cause or an effect of poor health.
The Study: Researchers used data from Danish government health records on 95,766 subjects. All were tested for a genetic variant that reduces their vitamin D levels, and 35,334 also had their vitamin D serum levels measured. There were 10,349 deaths over the course of the study, from 1981 to 2013.
Results: Having the genes associated with lifelong vitamin D increases the risk of cancer death by more than 1.4x, and death from any cause by more than 1.3x.
My Take: This study shows there may be a causal relationship between low vitamin D levels and death. Still, this study is not sufficient to recommend that you go out and buy supplements. We need randomized trials to recommend that. For me personally, I have no issues with taking 2000 IU of vitamin D daily. Whether I can modify my disease risk by doing so, however, is speculation. Sunshine is a remarkably efficient way to make vitamin D, but don’t overdo (We don’t need you getting skin cancer)! I’m Dr. Michael Hunter.
The small print: The material presented herein is informational only, and is not designed to provide specific guidance for an individual. Please check with a valued health care provider with any questions or concerns. As for me, I am a Harvard- , Yale- and UPenn-educated radiation oncologist, and I practice in the Seattle, WA (USA) area. I feel genuinely privileged to be able to share with you. If you enjoyed today’s offering, please consider clicking the follow button at the bottom of this page.
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Reference: BMJ 2014; 349 doi: http://dx.doi.org/10.1136/bmj.g6330 (Published 18 November 2014)