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Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of aggregate data from randomised controlled trials

David A. Jolliffe, C. Camargo, J. Sluyter, M. Aglipay, J. Aloia, D. Ganmaa, P. Bergman, A. Borzutzky et al.

medRxiv, 2020

30,956 participants · 258 citations

Abstract

Objectives: To assess the overall effect of vitamin D supplementation on risk of acute respiratory infection (ARI), and to identify factors modifying this effect. Design: We conducted a systematic review and meta-analysis of data from randomised controlled trials (RCTs) of vitamin D for ARI prevention using a random effects model. Pre-specified sub-group analyses were done to determine whether effects of vitamin D on risk of ARI varied according to baseline 25-hydroxyvitamin D (25[OH]D) concentration or dosing regimen. Data Sources: MEDLINE, EMBASE, the Cochrane Central Register of Controlled Trials (CENTRAL), Web of Science, ClinicalTrials.gov and the International Standard RCT Number (ISRCTN) registry from inception to May 2020. Eligibility Criteria for Selecting Studies: Double-blind RCTs of supplementation with vitamin D or calcidiol, of any duration, were eligible if they were approved by a Research Ethics Committee and if ARI incidence was collected prospectively and pre-specified as an efficacy outcome. Results: We identified 40 eligible RCTs (total 30,956 participants, aged 0 to 95 years). Data were obtained for 29,841 (96.5%) of 30,909 participants in 39 studies. For the primary comparison of vitamin D supplementation vs. placebo, the intervention reduced risk of ARI overall (Odds Ratio [OR] 0.89, 95% CI 0.81 to 0.98; P for heterogeneity 0.009). No statistically significant effect of vitamin D was seen for any of the sub-groups defined by baseline 25(OH)D…

How strong is the evidence?

Evidence Hub reads this as a meta-analysis, done in people. Its evidence level is 1 of 5 (Highest · pooled evidence). Pooled evidence from several studies sits at the top of the evidence pyramid. Reported size: 30,956 participants or records.

How the five levels of evidence work. The level is assigned automatically from the abstract and can be wrong, so check the paper.

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