Vitamin C and COVID-19 treatment: A systematic review and meta-analysis of randomized controlled trials

source extracted confidence: high 2026-04-09
#antioxidants #ascorbic-acid #covid-19 #dietary-supplements #humans

Vitamin C and COVID-19 treatment: A systematic review and meta-analysis of randomized controlled trials

Rawat et al., 2021 | Diabetes Metab Syndr | Meta Analysis

Citation

Rawat Dimple, Roy Avishek, ... Baidya Dalim Kumar. Vitamin C and COVID-19 treatment: A systematic review and meta-analysis of randomized controlled trials. Diabetes Metab Syndr. 2021;15(6):102324. doi:10.1016/j.dsx.2021.102324

Abstract

BACKGROUND AND AIMS: Vitamin C has been used as an anti-oxidant in various diseases including viral illnesses like coronavirus disease (COVID-19). METHODS: Meta-analysis of randomized controlled trials (RCT) investigating the role of vitamin C supplementation in COVID-19 was carried out. RESULTS: Total 6 RCTs including n = 572 patients were included. Vitamin C treatment didn't reduce mortality (RR 0.73, 95% CI 0.42 to 1.27; I2 = 0%; P = 0.27), ICU length of stay [SMD 0.29, 95% CI -0.05 to 0.63; I2 = 0%; P = 0.09), hospital length of stay (SMD -0.23, 95% CI -1.04 to 0.58; I2 = 92%; P = 0.57) and need for invasive mechanical ventilation (Risk Ratio 0.93, 95% CI 0.61 to 1.44; I2 = 0%; P = 0.76). Further sub-group analysis based on severity of illness (severe vs. non-severe), route of administration (IV vs. oral) and dose (high vs. low) failed to show any observable benefits. CONCLUSION: No significant benefit noted with vitamin C administration in COVID-19. Well-designed RCTs with standardized control group needed on this aspect.

Key Findings

Total 6 RCTs including n = 572 patients were included. Vitamin C treatment didn't reduce mortality (RR 0.73, 95% CI 0.42 to 1.27; I2 = 0%; P = 0.27), ICU length of stay [SMD 0.29, 95% CI -0.05 to 0.63; I2 = 0%; P = 0.09), hospital length of stay (SMD -0.23, 95% CI -1.04 to 0.58; I2 = 92%; P = 0.57) and need for invasive mechanical ventilation (Risk Ratio 0.93, 95% CI 0.61 to 1.44; I2 = 0%; P = 0.76). Further sub-group analysis based on severity of illness (severe vs. non-severe), route of admini

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population See abstract
Sample Size 572
Age Range See abstract
Condition See abstract

MeSH Terms

  • Antioxidants
  • Ascorbic Acid
  • COVID-19
  • Dietary Supplements
  • Humans
  • Length of Stay
  • Randomized Controlled Trials as Topic
  • COVID-19 Drug Treatment

Evidence Classification

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

Provenance

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