Effect of vitamin C supplementation on outcomes in patients with COVID-19: a systematic review and meta-analysis

source extracted confidence: high 2026-04-09

Effect of vitamin C supplementation on outcomes in patients with COVID-19: a systematic review and meta-analysis

Xu et al., 2024 | Front Nutr | Systematic Review

Citation

Xu Wenhao, Wang Peng, ... Zhang Yu. Effect of vitamin C supplementation on outcomes in patients with COVID-19: a systematic review and meta-analysis. Front Nutr. 2024;11:1465670. doi:10.3389/fnut.2024.1465670

Abstract

BACKGROUND: Since the emergence of the coronavirus disease 2019 (COVID-19) pandemic, caused by the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2), millions of lives have been lost, posing formidable challenges to healthcare systems worldwide. Our study aims to conduct a meta-analysis to evaluate the efficacy of vitamin C supplementation in reducing in-hospital mortality rates and shortening the length of ICU or hospital stays among patients diagnosed with COVID-19. METHODS: A comprehensive systematic review and meta-analysis was conducted, sourcing data from PubMed, Embase, Scopus, and the Cochrane Central Register of Controlled Trials. Our analysis focused on randomized clinical trials comparing the efficacy of vitamin C supplementation with standard care in adult COVID-19 patients. RESULTS: Through meticulous examination of 11 clinical trials, our meta-analysis found that vitamin C supplementation did not reduce in-hospital mortality rates in COVID-19 patients compared to those receiving standard care (Risk Ratio [RR] = 0.85; 95% Confidence Interval [CI]: 0.62-1.17; p = 0.31). Similarly, the analysis indicated no significant difference in the length of ICU stays between both cohorts. Additionally, the occurrence of other adverse events was found to be similar across both groups treated with vitamin C supplementation and standard care (all p > 0.05). CONCLUSION: Vitamin C supplementation did not reduce in-hospital mortality or ICU stay durations in patients with COVID-19. The interpretation of these findings is limited by the small number of available studies and participants, which affects the strength of the conclusions. CLINICAL TRIAL REGISTRATION: Identifier CRD42024497474.

Key Findings

Through meticulous examination of 11 clinical trials, our meta-analysis found that vitamin C supplementation did not reduce in-hospital mortality rates in COVID-19 patients compared to those receiving standard care (Risk Ratio [RR] = 0.85; 95% Confidence Interval [CI]: 0.62-1.17; p = 0.31). Similarly, the analysis indicated no significant difference in the length of ICU stays between both cohorts. Additionally, the occurrence of other adverse events was found to be similar across both groups tre

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population adult covid
Sample Size 19
Age Range See abstract
Condition See abstract

MeSH Terms

  • No MeSH terms indexed

Evidence Classification

  • Level: Systematic Review
  • Publication Types: Journal Article, Systematic Review
  • Vertical: vitamin-c

Provenance

Source extracted via PubMed E-utilities API on 2026-04-09