Research · Meta-analysis
Vitamin D supplementation to prevent acute respiratory tract infections: systematic review and meta-analysis of individual participant data
What it found
Vitamin D modestly reduced the odds of at least one acute respiratory infection (aOR 0.88), with a much larger benefit in severely deficient people (aOR 0.58) and only for daily/weekly — not bolus — dosing.
- Design
- Meta-analysis
- Year
- 2017
- Sample size
- 10,933
- Population
- participants of all ages across 25 RCTs
- Intervention
- vitamin D (daily, weekly, or bolus) vs placebo
- Outcome
- incidence of acute respiratory tract infection
- Journal
- BMJ
Citation last checked 2026-06-21.