# Vitamin D Respiratory Infection Meta-analysis: What the Evidence Says
Canonical: https://www.migaku.app/guides/vitamin-d-respiratory-infection-meta-analysis-evidence-review
Category: evidence-review
Summary: Vitamin D Respiratory Infection Meta-analysis has 2 source documents in the current Migaku evidence database. The strongest available sources in this first pa
Last reviewed: 2026-05-27
Reviewed by: Migaku Evidence Review
# Vitamin D Respiratory Infection Meta-analysis: What the Evidence Says

## Quick Answer

Vitamin D Respiratory Infection Meta-analysis has 2 source documents in the current Migaku evidence database. The strongest available sources in this first pass are mixed biomedical and public-health sources, so conclusions should be framed as evidence-aware guidance rather than medical advice.

## Key Takeaways

- This page is generated only from sources stored in the Migaku evidence knowledge base.
- Current evidence mix: 1 narrative review, 1 preclinical study.
- Claims should be interpreted with the source type, study design, population, and publication date in mind.
- This article is educational and does not replace care from a qualified clinician.

## Evidence Map

| Source | Evidence type | Level | Date | Identifier |
| --- | --- | ---: | --- | --- |
| Vitamin D and Health Outcomes: State-of-the-Art Review of Triangulated Evidence and Ongoing Controversies | narrative review | 3 | 2026-03-18 | 10.1007/s13668-026-00748-2 |
| Vitamin D in Infectious Diseases: A Narrative Review Focusing on COVID-19, Long COVID, and Influenza | preclinical study | 4 | 2026-02-14 | 10.3390/nu18040634 |

## What The Sources Report

- Observational studies have consistently reported associations between low serum 25(OH)D concentrations and increased risks of cardiovascular disease (CVD), diabetes, cancer, autoimmune disorders, respiratory infections, adverse pregnancy outcomes, and all-cause mortality. [Dalamaga Maria (2026); evidence level 3]
- High-risk groups include older adults, individuals with obesity, darker skin pigmentation, limited sun exposure, and those with chronic kidney or liver disease or malabsorptive disorders. [Dalamaga Maria (2026); evidence level 3]
- Vitamin D has traditionally been known for its role in bone and mineral metabolism, but accumulating evidence demonstrates that it also plays an important role in immune regulation and host defense against infections. [Caliman-Sturdza Olga Adriana (2026); evidence level 4]
- We bring to the fore important mechanisms, observational and interventional study findings, emerging evidence about long COVID, preliminary influenza prevention evidence, pertinent meta-analyses, guidelines, and controversies. [Caliman-Sturdza Olga Adriana (2026); evidence level 4]

## How To Read This Evidence

Evidence level 1 generally reflects systematic reviews or meta-analyses. Level 2 includes randomized trials, guidelines, or public-health guidance. Level 3 usually reflects observational or narrative-review evidence. Level 4 is weaker or early-stage evidence. The level is a sorting aid, not a final quality grade.

## Practical Interpretation

For vitamin d respiratory infection meta-analysis, the current source set is useful for orientation, but it is not yet broad enough for strong claims. Use cautious language and keep conclusions close to the cited sources.

## Limits Of This First Pass

This is a small-batch MVP article. It uses the first ingested sources for this topic and should be expanded with more targeted searches, license review, and human editorial checks before being treated as a definitive review.

## References

- Dalamaga Maria (2026). Vitamin D and Health Outcomes: State-of-the-Art Review of Triangulated Evidence and Ongoing Controversies. DOI: 10.1007/s13668-026-00748-2. PMCID: PMC12999768. PMID: 41849024. License: CC BY 4.0. https://pmc.ncbi.nlm.nih.gov/articles/PMC12999768/
- Caliman-Sturdza Olga Adriana (2026). Vitamin D in Infectious Diseases: A Narrative Review Focusing on COVID-19, Long COVID, and Influenza. DOI: 10.3390/nu18040634. PMCID: PMC12943368. PMID: 41754151. License: CC BY 4.0. https://pmc.ncbi.nlm.nih.gov/articles/PMC12943368/

## Safety Note

Health information can change, and individual risk depends on medical history, medications, pregnancy status, age, and diagnosis. Talk with a qualified clinician before changing treatment, supplement, or medication routines.