In Reply We thank the correspondents for their thoughtful letters. We agree that the Vitamin D Assessment Study1 has limited power to detect beneficial effects in people with low 25-hydroxyvitamin D (25[OH]D) concentrations, particularly in people with very low 25(OH)D concentrations (less than 12 ng/mL), as we stated in the study limitations. While it is possible that a larger study may detect such an effect, the fact that we did not see a signal in people with 25(OH)D levels less than 20 ng/mL, with the hazard ratio in this group equal to 1.00 (Table 31) and very similar to the overall study result (hazard ratio, 1.02),1 suggests that the response does not vary with baseline vitamin D status. Recent meta-analyses of cohort studies, which all show a significantly increased risk of cardiovascular disease (CVD) in people with baseline 25(OH)D concentrations in the range of 12 to 20 ng/mL, support the relevance of our results for people with 25(OH)D concentrations up to 20 ng/mL.2-4
Scragg R, Camargo CA. Vitamin D Supplementation and Cardiovascular Disease Risk—Reply. JAMA Cardiol. 2017;2(11):1282. doi:10.1001/jamacardio.2017.2941
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