To the Editor: Dr Sanders and colleagues1 studied the effects of a single annual dose of 500 000 IU of cholecalciferol in older women and found an increase in falls and fractures. The authors suggested that such an increase may depend on the high total annual dose used in the study, but they did not present any hypothesis for the underlying mechanism of this phenomenon.
Malgarini RB, Pimpinella G. High-Dose Oral Vitamin D Supplementation and Risk of Falls in Older Women. JAMA. 2010;304(8):854-857. doi:10.1001/jama.2010.1168