Effect of vitamin D, calcium, or combined supplementation on fall prevention: a systematic review and updated network meta-analysis.

Background: The association between vitamin D supplementation and the risk of falls in older adults has been controversial. This systematic review and network meta-analysis aims to assess the efficacy of vitamin D, calcium, and combined supplementation in the prevention of falls. Methods: Randomized controlled trials (RCTs) on the efficacy of vitamin D in fall prevention were systematically searched in PubMed, Embase, Cochrane Library, and Web of Science from inception to May 9, 2023. The network meta-analysis was performed using a random effects model in R4.1.3 and Stata15.0. Heterogeneity was evaluated by the I² statistic, and publication bias was assessed using funnel plots, Begg's test, and Egger's tests. Data were pooled and expressed as relative risk (RR) and 95% confidence interval (CI). Results: A total of 35 RCTs involving 58,937 participants were included in this study, among which 11 RCTs (31.4%) applied calcium combined with vitamin D. There was low heterogeneity (I² = 11%) among the included studies. Vitamin D supplementation at 800–1000 International Unit (IU)/d resulted in a lower risk of falls than placebo or no treatment (RR = 0.85, 95%CI: 0.74–0.95). In addition, 800–1000 IU/d of vitamin D with or without calcium were more effective in preventing falls than calcium alone. High-dose vitamin D (> 1000 IU/day) increased the risk of falls compared with 800–1000 IU/d of vitamin D. According to the subgroup analysis, daily administration of 800–1000 IU/d vitamin D was associated with a 22% reduction in the risk of falls (RR = 0.78, 95%CI:0.64–0.92), whereas intermittent vitamin D administration had no preventive effect. Furthermore, 800–1000 IU/d of vitamin D also significantly decreased the risk of falls in old adults with ≤ 50 nmol/L 25-hydroxyvitamin D [25(OH)D] (RR = 0.69, 95%CI:0.52–0.86) but not in individuals with > 50 nmol/L 25(OH)D. Conclusion: Vitamin D supplementation at 800–1000 IU/d is associated with a lower risk of falls among older adults. 800-1000IU/d of vitamin D has a benefit on prevention of falls in population received daily dose regimens and in population with vitamin D deficiency. [ABSTRACT FROM AUTHOR]