Tier 1 — highest

Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data

Adrian R Martineau, David A Jolliffe, Richard L Hooper, Lauren Greenberg, John F Aloia, Peter Bergman, Gal Dubnov-Raz, Susanna Esposito, Davaasambuu Ganmaa, Adit A Ginde, Emma C Goodall, Cameron C Grant, Christopher J Griffiths, Wim Janssens, Ilkka Laaksi, Semira Manaseki-Holland, David Mauger, David R Murdoch, Rachel Neale, Judy R Rees, Steve Simpson, Iwona Stelmach, Geeta Trilok Kumar, Mitsuyoshi Urashima, Carlos A Camargo
BMJ (Clinical research ed.) 2017 356:i6583

Bibliography

PubMed
PMID 28202713
PubMed Central
PMC5310969
Funding
Support is recorded from NHLBI NIH HHS, Department of Health, Medical Research Council. See the original publication for grant and material-support details.
Competing interests
The publication includes author disclosures; consult the linked source for the individual relationships and their relevance.

Study snapshot

DesignSystematic review and meta-analysis
ModelHuman evidence synthesis
SampleIndividual-participant data for 10,933 people from 25 randomized trials
InterventionVitamin D2 or D3 versus placebo; daily, weekly and bolus schedules
DurationVaried across trials
EndpointsAcute respiratory tract infection; Effect modification by baseline status and schedule

What the study showed, in plain terms

This publication examines acute respiratory tract infection, effect modification by baseline status and schedule. Study population or evidence base: Individual-participant data for 10,933 people from 25 randomized trials. Intervention or exposure: Vitamin D2 or D3 versus placebo; daily, weekly and bolus schedules.

Key findings

This 2017 analysis reported lower respiratory-infection risk, with stronger signals in severe deficiency and regular dosing without additional boluses.

What this study can and cannot tell us

The analysis is historical and overlaps later updates. The 2025 pooled evidence did not establish significant overall protection or consistent subgroup modification.

Editorial review

Reviewed by the Biohack Blueprint research team

Last verified

Biohack Blueprint Research