To the Editor: The study by Dr Sanders and colleagues1 found an association between annual high-dose vitamin D supplementation (500 000 IU of cholecalciferol administered orally in autumn or winter) and an increased risk of falls and fractures. These results are counter to previous evidence based on clinical trials and a meta-analysis2 that suggested that high-dose supplemental vitamin D reduced fall risk by 19% (pooled relative risk, 0.81; 95% confidence interval [CI], 0.71-0.92). It is even more concerning that the observed increase in fall risk was more evident in the first 3 months following dosing, which makes causality more plausible.
Prieto-Alhambra D, Judge A, Pazianas M. High-Dose Oral Vitamin D Supplementation and Risk of Falls in Older Women. JAMA. 2010;304(8):854-857. doi:10.1001/jama.2010.1166