The efficacy of intravenous vitamin C in critically ill patients: A meta-analysis of randomized controlled trials

Background & aims: A large number of clinical studies have shown that intravenous vitamin C supplementation is beneficial for critically ill patients, but current research conclusions are controversial. This meta-analysis included high-quality randomized controlled trials (RCTs) to evaluate the efficacy of intravenous vitamin C in critically ill patients. Methods: We searched PubMed, EMBASE and the Cochrane Library from inception to August 15, 2020 to identify published reports of RCTs evaluating the role of intravenous vitamin C in critically ill patients. Risk ratios values (RRs) and 95% confidence intervals (CIs) were calculated by random-effects metaanalysis. Trial sequential analysis (TSA), meta-regression, subgroup analyses and sensitivity analyses were also performed. Results: Our meta-analysis included 18 RCTs involving 2001 patients (1005 with vitamin C treatment and 996 control treatment). Intravenous vitamin C administration reduced the intensive care unit (ICU) length of stay (LOS) (MD = -0.36, 95% CI: -0.60 to -0.11, P = 0.004) and hospital LOS (MD = -1.50, 95% CI: -2.64 to -0.35, P = 0.01) but had no significant effect on the longest follow-up mortality, hospital or ICU mortality and change in Sequential Organ Failure Assessment (SOFA) score. TSAs for mortality, ICU and hospital LOS were inconclusive. Conclusions: Intravenous vitamin C administration may shorten ICU LOS and hospital LOS. It had no effect on mortality and organ failure. All TSAs were inconclusive, and the value of vitamin C for critically ill patients needs to be demonstrated in more high-quality RCTs. (c) 2021 Elsevier Ltd and European Society for Clinical Nutrition and Metabolism. All rights reserved.

Automated summary

Intravenous vitamin C administration may reduce ICU and hospital length of stay for critically ill patients, but has no significant effect on mortality or organ failure. The results of trial sequential analysis were inconclusive, indicating a need for more high-quality RCTs to confirm the value of vitamin C for critically ill patients.