JoAnn Manson, et al. New England Journal of Medicine, November 10, 2016 (http://www.nejm.org/doi/full/10.1056/NEJMp1608005)
EVERYBODY CALM DOWN!
Commentary:
Having practiced medicine for more than 30 years, I have witnessed diagnostic and treatment trends come and go, not unlike diet fads. Both lay person and physician need reality checks periodically, especially by using sound scientific data. In recent years, “Vitamin D deficiency” has become the mantra for many patients and physicians alike as an explanation for many ailments otherwise unexplained. As a medical skeptic, I have watched the Vitamin D literature proliferate uncontrollably, providing easy explanations for numerous disease conditions. I love Hans Christian Andersen’s 1837 story “The Emperor’s New Clothes”, where a little boy was the only one in the crowd who innocently dared to tell the stark truth that “…the Emperor has no clothes…”. The article above is a modern rendition of Andersen’s story- it is a sobering look at the Vitamin D fad and the erroneous assumption as to what constitutes a “normal” blood level.
Bottom line:
“The reality is that the majority (of the population) has a requirement of 20 ng per ml or less” (20 is the perceived cutoff for “normal” blood level of Vit D). Using 20 as a cutoff misclassifies much of the population as “deficient”, leading to unnecessary supplementation with mega doses of Vitamin D and erroneous association with disease conditions. This is a trap into which patients and physicians alike innocently fall, desperately trying to explain and treat various abnormal medical conditions. Manson et al conclude the article by saying “Although clinical judgement and customized interventions can be used with individual patients, avoidance of overscreening and overprescribing of supplemental vitamin D remains important”. I personally would like to remind myself and my physician colleagues to temper our tendency to scapegoat Vitamin D for many of mankind’s ailments; read the medical literature carefully; and treat cutoff values with healthy skepticism.