The Effect of Vitamin D 3 Supplementation on the Risk of Falls in a General Population—The Finnish Vitamin D Trial

ABSTRACT Background The impact of vitamin D on fall incidence remains controversial. We studied the effect of 5 years of vitamin D 3 supplementation on the risk of falls in a double‐blind, placebo‐controlled randomized trial with generally healthy, community‐dwelling men and women in Finland. Methods The study included 2495 participants, men aged ≥ 60 and women aged ≥ 65, who were randomized into three arms: 1600 IU/day or 3200 IU/day of vitamin D 3 or placebo. A random subgroup of 551 participants underwent more detailed examinations. Falls and fall‐related injuries were collected with questionnaires at months 0, 12, 24, 36, and 60. General linear mixed models and generalized linear models were used for analyses. Results Over the 5‐year follow‐up, a similar fall risk of 55% and fall‐injury risk of 11% were observed in the placebo, 1600 IU/day, and 3200 IU/day arms, with the mean number of falls and fall‐injuries per person‐year of 1.26 (95% CI 1.14–1.38) and 0.07 (95% CI 0.06–0.08), respectively. Age, sex, or BMI did not modify the results. In the random subgroup, the mean baseline serum 25(OH)D concentration was 75 nmol/L (SD 18). After 12 months, the concentrations were 73, 100, and 120 nmol/L in the placebo, 1600 IU/day, and 3200 IU/day arms, respectively. Conclusions Five‐year vitamin D 3 supplementation of 1600 IU/day or 3200 IU/day did not affect the overall risk of falls or fall injuries among generally healthy, largely vitamin D sufficient men and women. The findings do not support the use of high vitamin D doses for fall prevention in such populations. Trial Registration ClinicalTrials.gov : NCT01463813, https://clinicaltrials.gov/ct2/show/NCT01463813