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Vitamins and Minerals (Poster Session)

(P30-033-25) Vitamin D Supplementation and Its Effect on Respiratory Tract Infections: A Meta-Analysis of Randomized Controlled Trials

Monday, June 2, 2025
11:45 AM - 12:45 PM ET
Location: Poster Board E-29

    Presenting Author(s)

  • Tianou Zhang, PhD

    Assistant Professor
    University of the Pacific
    Stockton, California, United States

    • Co-Author(s)

  • JL

    Joon Lee

    University of the Pacific
    Stockton, California, United States

  • CN

    Celine Nguyen

    University of the Pacific
    Stockton, California, United States

Disclosure(s):
Tianou Zhang, PhD: No relevant financial relationship(s) with ineligible companies to disclose.


Objectives: Vitamin D has been implicated in the prevention of respiratory tract infections (RTIs), but evidence remains inconsistent. This meta-analysis evaluated the effect of vitamin D supplementation on RTI incidence based on clinical studies published from 2009 to 2019.

Methods: Data from 18 trials (n = 11,183 participants) were included to assess the effect of vitamin D supplementation on RTI incidence. Odds ratios (ORs) with 95% confidence intervals (CIs) were calculated using a random-effects model. Heterogeneity was assessed using I² statistics.

Results: The pooled OR for RTI prevention was 0.74 (95% CI: 0.60–0.92, p < 0.01), indicating a statistically significant reduction in RTI incidence with vitamin D supplementation. Subgroup analysis demonstrated notable protective effects in participants with baseline vitamin D deficiency (OR: 0.43; 95% CI: 0.25–0.72). However, results varied across studies, with some reporting no significant benefit. Moderate heterogeneity was observed (I² = 57%, p = 0.002), reflecting variability in study populations, dosing regimens, and durations.

Conclusions: Vitamin D supplementation significantly reduces the risk of RTIs, particularly in deficient populations. Findings suggest that addressing vitamin D deficiency through supplementation could be an effective public health strategy to reduce RTI incidence. Further studies are needed to determine optimal dosing and target populations.

Funding Sources: Nothing to disclose