Vitamin C for the Management of COVID-19: a Systematic Review and
Meta-analysis of Randomized Controlled Trials
Abstract
Vitamin C is a vital nutrient that functions as an antioxidant and is
important as a co-factor and regulator of several immune system
pathways. The role of vitamin C in the treatment of COVID-19 is largely
debatable. We conducted this meta-analysis to evaluate the efficacy and
safety of vitamin C in the treatment of COVID-19. We searched several
electronic databases from inception to March 2023 to retrieve randomized
controlled trials on the use of Vitamin C for COVID-19. RevMan 5.4 was
used to calculate risk ratios (RRs) and Mean Differences (MDs) along
with confidence intervals (95% CI) using a random-effects model. We
included 9 randomized controlled trials in our meta-analysis. Vitamin C
did not reduce the all-cause mortality in patients with COVID-19
compared to the standard treatment [RR 0.86, 95% CI: 0.65-1.14; I
2=66%]. Vitamin C was found to be associated with
an increased incidence of ventilation in COVID-19 patients when compared
to standard treatment [RR 1.37, 95% CI: 1.18-1.59; I
2=58%]. There were no significant differences
between both groups regarding the incidence of hospitalization [RR
1.00, 95% CI: 0.98-1.02; I 2=0%], incidence of
recovery [RR 1.57, 95% CI: 0.45-5.50; I 2=52%],
hospital mortality [RR 0.68, 95% CI: 0.44-1.06; I
2=0%] and length of hospital stay [MD -0.63, 95%
CI: -3.04 to 1.78; I 2=81%]. Vitamin C
administration did not reduce all-cause mortality in COVID-19 patients.
Additional studies are required to evaluate the role of Vitamin C in the
prevention and treatment of COVID-19 especially in ICU patients.