Vitamin D results in more-not fewer-falls and fractures in older women

Older community-dwelling women who receive annual high-dose cholecalciferol (vitamin D) experience more falls and fractures-and more fractures unrelated to falls-than those who do not. This unexpected adverse outcome may be dose-related.

Sanders and associates randomly assigned 2317 women aged 70 years and older to receive a single dose of cholecalciferol, 500,000 IU, or placebo each year for 3 to 5 years. The single-dose design was intended to circumvent the common problem of noncompliance. The study participants reported episodes of falls and fractures via postcard or telephone.

The women who received vitamin D had 15% more falls and 26% more fractures than those taking placebo. Per 100 person-years, the rate of falls was 83.4 for the vitamin D group and 72.7 for the placebo group. Fracture rates were 4.9 and 3.9 per 100 person-years in the vitamin D and placebo groups, respectively. Falls and fractures were most common during the first 3 months of treatment, causing the investigators to speculate that the high dose and infrequent administration may have contributed to the regimen’s detrimental effect.

The authors noted that the safety of high-dose vitamin D supplementation warrants further study.