Vitamin C Administration to the Critically Ill: A Systematic Review and Meta-Analysis

source extracted confidence: high 2026-04-09
#antioxidants #ascorbic-acid #critical-care #critical-illness #hospital-mortality

Vitamin C Administration to the Critically Ill: A Systematic Review and Meta-Analysis

Langlois et al., 2019 | JPEN J Parenter Enteral Nutr | Meta Analysis

Citation

Langlois Pascal L, Manzanares William, ... Heyland Daren K. Vitamin C Administration to the Critically Ill: A Systematic Review and Meta-Analysis. JPEN J Parenter Enteral Nutr. 2019-Mar;43(3):335-346. doi:10.1002/jpen.1471

Abstract

Vitamin C, an enzyme cofactor and antioxidant, could hasten the resolution of inflammation, oxidative stress, and microvascular dysfunction. While observational studies have demonstrated that critical illness is associated with low levels of vitamin C, randomized controlled trials (RCTs) of vitamin C, alone or in combination with other antioxidants, have yielded contradicting results. We searched MEDLINE, EMBASE, CINAHL, and the Cochrane Central Register of Controlled Trials (inception to December 2017) for RCTs comparing vitamin C, by enteral or parenteral routes, with placebo or none, in intensive care unit (ICU) patients. Two independent reviewers assessed study eligibility without language restrictions and abstracted data. Overall mortality was the primary outcome; secondary outcomes were incident infections, ICU length of stay (LOS), hospital LOS, and duration of mechanical ventilation (MV). We prespecified 5 subgroups hypothesized to benefit more from vitamin C. Eleven randomized trials were included. When 9 RCTs (n = 1322) reporting mortality were pooled, vitamin C was not associated with reduced risk of mortality (risk ratio [RR] 0.72, 95% confidence interval [CI]: 0.43-1.20, P = .21). No effect was found on infections, ICU or hospital LOS, or duration of MV. In multiple subgroup comparison, no statistically significant subgroup effects were observed. However, we did observe a tendency towards a mortality reduction (RR 0.21; 95% CI: 0.04-1.05; P = .06) when intravenous high-dose vitamin C monotherapy was administered. Current evidence does not support supplementing critically ill patients with vitamin C. A moderately large treatment effect may exist, but further studies, particularly of monotherapy administration, are warranted.

Key Findings

A moderately large treatment effect may exist, but further studies, particularly of monotherapy administration, are warranted.

Outcomes Measured

  • Requires manual extraction

Population

Field Value
Population vitamin c
Sample Size 1322
Age Range See abstract
Condition stress

MeSH Terms

  • Antioxidants
  • Ascorbic Acid
  • Critical Care
  • Critical Illness
  • Hospital Mortality
  • Humans
  • Length of Stay
  • Respiration, Artificial
  • Treatment Outcome

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