Hemilä · Nutrients 2019 · meta-analysis of controlled trials · n=18 trials (2004 patients)

Vitamin C Can Shorten the Length of Stay in the ICU: A Meta-Analysis.

Cited 262 times in the scientific literature.

Level 1 - systematic review of randomized trials

Meta-analysis of 18 controlled clinical trials

PubMed 30934660 · doi:10.3390/nu11040708 · record verified 2026-08-30

What was done

A meta-analysis of 18 controlled trials comprising 2,004 patients (13 trials in elective cardiac surgery) evaluated whether vitamin C administration reduces ICU length of stay and duration of mechanical ventilation. Inverse variance, fixed-effect modeling on the ratio of means scale was used.

What was found

Across 12 trials (n = 1,766), vitamin C reduced ICU stay by 7.8% (95% CI: 4.2% to 11.2%; p = 0.00003). In six trials using oral vitamin C at 1–3 g/day (mean 2.0 g/day), ICU stay decreased by 8.6% (p = 0.003). In three trials with patients requiring mechanical ventilation for over 24 hours, vitamin C shortened ventilation duration by 18.2% (95% CI: 7.7% to 27%; p = 0.001).

Why it matters

Even modest percentage reductions in ICU duration and mechanical ventilation offer meaningful clinical and economic value given the low cost and accessibility of vitamin C.

Limits

Thirteen of the 18 trials were limited to elective cardiac surgery cohorts, restricting generalizability to general ICU populations. The mechanical ventilation analysis relied on only three trials, and the use of fixed-effect pooling may underestimate variability across distinct clinical protocols.

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