Evidence map›Paper›PMID 23840373›Full record

SynthesisPloS one2013

Vitamin D and Respiratory Tract Infections: A Systematic Review and Meta-Analysis of Randomized Controlled Trials.

Peter Bergman, Asa U Lindh, Linda Björkhem-Bergman, Jonatan D Lindh

Registry-linked trialOpen access · goldAbstract readMeta-AnalysisSystematic Review
PubMed Full text at PMC Publisher
In one paragraph

Synthesis in PloS one, 2013. The graph could read no effect estimate from its abstract, so it casts no vote on the map. It is linked to trial NCT04519034 (Retrospective Pilot Study of Vitamin D Status and Immune-inflammatory Status in Different UK Populations With COVID-19 Infection), which is not on this map. Cited by 199 papers, 20 of them syntheses that pooled it.

0numbers the graph read from it
0cells of the map it votes in
199citing papers in PubMed, 20 pooled it
19.9field-weighted citation impact, top 1% of its field
1 · What the graph read from it

What it found

Each row is one number read from the abstract, on the scale the paper reported it, with its interval. Left of the dashed line favours the treatment, right favours the comparator. Under each row is the sentence it came from. New to these charts? A ten-minute tutorial.

The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

The trial behind it

Trials whose registry record cites this paper, or whose number appears in the abstract. A trial that started after this paper was published is citing it as background, not reporting it.

NCT04519034 completednot on this mapstarted 2020, after this paper: background citation

Retrospective Pilot Study of Vitamin D Status and Immune-inflammatory Status in Different UK Populations With COVID-19 Infection

TypeobservationalSponsorGuy's and St Thomas' NHS Foundation TrustRan2020 to 2021Enrolled27,628ConditionsCovid19Armsno intervention
3 · Its place in the literature

Who cites it

199 citing papers in PubMed, 20 syntheses or guidelines pooled it, 424 citations in OpenAlex.

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139 more citing papers are in PubMed but not listed here.

4 · The record

Corrections and comments

PubMed lists nothing against this paper. Absence here is not a guarantee, only a check that was made.

5 · Who and what money

Authors and funding

4 authors at 2 institutions in 1 country.

Peter BergmanDepartment of Laboratory Medicine, Division of Clinical Microbiology, Karolinska Institutet, Stockholm, Sweden ; Department of Medicine, Center for Infectious Medicine (CIM), Karolinska Institutet, Stockholm, Sweden.
Asa U Lindh
Linda Björkhem-Bergman
Jonatan D Lindh
Karolinska Institutet · SESaint Göran Hospital · SE

Funding

No grant is acknowledged in the PubMed record.

6 · The paper itself

Abstract

backgroundLow levels of 25-OH vitamin D are associated with respiratory tract infection (RTI). However, results from randomized controlled trials are inconclusive. Therefore, we performed a systematic review and meta-analysis to assess the preventive effect of vitamin D supplementation on RTI.

methodsRandomized, controlled trials of vitamin D for prevention of RTI were used for the analysis. The risks of within-trial and publication bias were assessed. Odds ratios of RTI were pooled using a random-effects model. Heterogeneity was assessed using Cochran's Q and I(2). Meta-regressions and subgroup analyses were used to assess the influence of various factors on trial outcome. The pre-defined review protocol was registered at the PROSPERO international prospective register of systematic reviews, registration number CRD42013003530.

findingsOf 1137 citations retrieved, 11 placebo-controlled studies of 5660 patients were included in the meta-analysis. Overall, vitamin D showed a protective effect against RTI (OR, 0.64; 95% CI, 0.49 to 0.84). There was significant heterogeneity among studies (Cohran's Q p<0.0001, I(2) = 72%). The protective effect was larger in studies using once-daily dosing compared to bolus doses (OR = 0.51 vs OR = 0.86, p = 0.01). There was some evidence that results may have been influenced by publication bias.

interpretationResults indicate that vitamin D has a protective effect against RTI, and dosing once-daily seems most effective. Due to heterogeneity of included studies and possible publication bias in the field, these results should be interpreted with caution.

Indexed as

Dietary SupplementsFemaleHumansMaleOdds RatioProspective StudiesRandomized Controlled Trials as TopicRespiratory Tract InfectionsTreatment OutcomeVitamin DVitamin D

Identifiers

PMID23840373
PMCPMC3686844
OpenAlexW2088966225

What OpenQuestion holds

Textmetadata
LicenceCC BY
Read underepoch 390

Registered trials

Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.