Vitamin D supplementation to prevent acute respiratory infections: systematic review and meta-analysis of stratified aggregate data
David A Jolliffe, Carlos A Camargo, John D Sluyter, Mary Aglipay, John F Aloia, Peter Bergman, Heike A Bischoff-Ferrari, Arturo Borzutzky, Vadim Y Bubes, Camilla T Damsgaard, Francine M Ducharme, Gal Dubnov-Raz, Susanna Esposito, Davaasambuu Ganmaa, Clare Gilham, Adit A Ginde, Inbal Golan-Tripto, Emma C Goodall, Cameron C Grant, Christopher J Griffiths, Anna Maria Hibbs, Wim Janssens, Anuradha Vaman Khadilkar, Ilkka Laaksi, Margaret T Lee, Mark Loeb, Jonathon L Maguire, Paweł Majak, Semira Manaseki-Holland, JoAnn E Manson, David T Mauger, David R Murdoch, Akio Nakashima, Rachel E Neale, Hai Pham, Christine Rake, Judy R Rees, Jenni Rosendahl, Robert Scragg, Dheeraj Shah, Yoshiki Shimizu, Steve Simpson-Yap, Geeta Trilok Kumar, Mitsuyoshi Urashima, Adrian R Martineau
The lancet. Diabetes & endocrinology·2025·13(4):307-320
Support is recorded from Australian National Health and Medical Research Council, Pharma Nord, NCCIH NIH HHS. See the original publication for grant and material-support details.
Competing interests
The source discloses financial, employment, advisory or material-support relationships involving Pharma Nord, DSM. See the publication for the authors and nature of each relationship.
Study snapshot
Design
Systematic review and meta-analysis
Model
Human evidence synthesis
Sample
40 placebo comparisons involving 61,589 participants for the primary pooled result
Intervention
Vitamin D supplementation across differing forms, doses and schedules
This publication examines acute respiratory infection risk, serious adverse events. Study population or evidence base: 40 placebo comparisons involving 61,589 participants for the primary pooled result. Intervention or exposure: Vitamin D supplementation across differing forms, doses and schedules.
Key findings
The updated 2025 analysis did not find statistically significant overall protection against acute respiratory infections. Prespecified subgroups did not identify a clear effect modifier.
What this study can and cannot tell us
Trials and regimens were heterogeneous, with possible small-study effects. This update overlaps and changes the interpretation of earlier positive respiratory meta-analyses.
