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

Abstract

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.

Keywords: Fall; Network meta-analysis; Supplement; Vitamin D.

Fig. 1

PRISMA flow diagram of study selection

Fig. 2

Summary of the risk of bias (using RoB2) in the included RCTs. (a) Results of each risk of bias item, presented as a percentage of included studies. (b) Results of the risk of bias in the 35 included trials

Fig. 3

Network meta-analysis maps of fall prevention effects of different vitamin D supplementation regimens

Fig. 4

Forest plot of the risk of falls

Fig. 5

Comparison of the effectiveness of different interventions based on the surface under the cumulative ranking curves (SUCRA). Note In this graphical approach, rankings are made based on the area under the curve (AUC). The greater the AUC, the higher the likelihood that an intervention is in the top rank or one of the top ranks

Fig. 6

Comparison-corrected funnel plot. A, ≤ 500 IU/d vitamin D; B, 600–700 IU/d vitamin D; C, 600-700IU/d vitamin D + Ca; D, 800–1000 IU/d vitamin D; E, 800–1000 IU/d vitamin D + Ca; F, 1100–1900 IU/d vitamin D; G, 1100–1900 IU/d vitamin D + Ca; H, ≥ 2000 IU/d vitamin D; I, Calcium; J, Placebo or no treatment

Fig. 7

Network meta-analysis maps of subgroup analyses. (a) Daily dosing regimens; (b) Intermittent dosing regimens; (c) Ambulatory and community-dwelling elderly; (d) Institution-dwelling elderly; (e) Mean baseline 25(OH)D concentration ≤ 50 nmol/L; (f) Mean baseline 25(OH)D concentration > 50 nmol/L; (g) Female subjects only; (h) Both male and female subjects

Fig. 8

Subgroup analysis of 800–1000 IU/d of vitamin D versus placebo or no treatment