Letters Section Editor: Jody W. Zylke, MD, Senior Editor.
Author Affiliations: Centre for Primary Care and Public Health, Queen Mary University of London, London, England (firstname.lastname@example.org).
To the Editor: Dr Levin and colleagues1 adopted a novel systematic approach to identify genetic variants modifying the influence of vitamin D on human health. Their findings have significance for the analysis and interpretation of the burgeoning number of clinical trials of vitamin D supplementation currently being undertaken worldwide. By way of validation, the variant in the VDR gene identified as modifying effects in their study (rs7968585) was found to be in linkage disequilibrium with another VDR variant (rs731236) that modified the effect of vitamin D supplementation on response to tuberculosis therapy.2 However, we wonder whether some aspects of their study design may have led to other potentially important effect-modifying variants being missed.
Martineau AR, Jolliffe DA. Genetic Variants Modifying the Influence of Vitamin D. JAMA. 2013;309(9):872-873. doi:10.1001/jama.2013.635