To the Editor: In their randomized controlled trial comparing annual high-dose oral vitamin D in older community-dwelling women, Dr Sanders and colleagues1 found a significantly greater relative risk of falls in the vitamin D group vs placebo group during the first 3 months of treatment than in the following 9 months. They also found a statistically nonsignificant greater risk of fractures in the first 3 months. It is not clear whether these adverse effects mainly occurred in the first month or between months 1 and 3, as may be expected with the precipitous drop in 25-hydroxycholecalciferol levels from months 1 to 3.
Mak JCS. High-Dose Oral Vitamin D Supplementation and Risk of Falls in Older Women. JAMA. 2010;304(8):854-857. doi:10.1001/jama.2010.1165