Association Between Vitamin D Supplementation and Fall Prevention: A Pool Evaluation

Background: Falls occur frequently among elderly individuals, leading to high morbidity and mortality. However, previous studies had inconsistent results regarding the association between vitamin D supplementation and falls. Objective: To assess the efficacy of vitamin D with or without calcium supplements in preventing elderly individuals from falling. Methods:  We searched the PubMed, Cochrane Library, and EMBASE databases systematically from their inception dates to June 10, 2020, using the keywords “vitamin D” and “fall” to identify systematic reviews and meta-analyses. Randomized controlled trials (RCTs) were identified from systematic reviews and meta-analyses. We performed an additional search to identify recently published RCTs (from database inception to February 15, 2020). The initial searches were updated on May 10, 2020. Double-blind RCTs comparing the effects of vitamin D with or without calcium supplements with those of a placebo or no treatment on fall incidence in adults older than 50 years. The data extraction and study quality assessment were performed by two independent reviewers. A meta-analysis was performed to calculate risk ratios (RRs), absolute risk differences (ARDs) and 95% CIs with random-effects models. Falling (i.e., unintentionally coming to rest on the ground, floor, or other lower level) was the main outcome. Fallers were people who experienced 1 or more falls. Results: A total of 38 RCTs involving 61 350 participants fulfilled the inclusion criteria. Compared with a placebo or no treatment, a high dose of vitamin D (≥700 IU) prevented falls (RR, 0.89 [95% CI 0.82 to 0.97]; ARD, -0.06 [95% CI, -0.09 to -0.02]). There was no significant association of low-dose vitamin D (<700 IU) with falling (RR, 1.09 [95% CI, 0.90 to 1.32]; ARD, 0.02 [95% CI, -0.05 to 0.10]). Subgroup analysis showed that supplemental calcium, 25(OH) D concentration and frequency influenced the effect of vitamin D in preventing falls. Sensitivity analysis showed that vitamin D prevented falls (RR, 0.92 [95% CI, 0.88 to 0.97]; ARD, -0.02 [95% CI -0.04 to -0.01]), which was consistent with the primary analysis. In addition, the active form of vitamin D also prevented falls (RR, 0.78 [95% CI 0.64 to 0.95]). Interpretation: In this meta-analysis of RCTs, doses of 700 IU to 2000 IU of supplemental vitamin D per day were associated with a lower risk of falling among ambulatory and institutionalized older adults. This benefit might depend on additional calcium supplementation. Funding: This study was supported by the National Natural Science Foundation of China. The National Natural Science Foundation of China Declaration of Interest: The authors declare no competing interests.