Role of intravenous vitamin C on outcomes in hospitalized patients with moderate or severe COVID-19: a real life data of Turkish patients

<bold>Background: </bold>We aimed to examine the efficacy of intravenous vitamin C (IV-VC) in the treatment of hospitalized patients with moderate or severe COVID-19. <bold>Method: </bold>We conducted a single-center and retrospective study including patients with COVID-19 diagnosis who were hospitalized. Patients were categorized into three groups as those who received low-dose (LDVC group, 2 g/day, n = 183) or high-dose IV-VC (HDVC group, 25 g/day, n = 41) and who did not receive IV-VC (control group, n = 46). <bold>Results: </bold>270 patients aged 19-97 years were enrolled. The median length of stay (LOS) was significantly high (9 days) in patients treated with high-dose VC when compared to patients treated with low-dose VC and control patients (6 vs 5 days, respectively). Need for intensive care unit (ICU) transfer was found to be significantly low in patients treated with low-dose VC (25.7%); contrarily, control patients had significantly higher rates of ICU transfer (67.4%), when compared to patients treated with high-dose VC (39%). Mortality of the LDVC group was significantly lower than that of the HDVC group (11.5 vs 29.3%). However, mortality rates were similar between the control and HDVC groups (21.7 vs 29.3%). According to the multivariate stepwise logistic regression mortality analysis, percent of change (triangle%)-BUN was the most significant variable (p < 0.001), the second significant variable was triangle%-AST (p = 0.002), the third significant variable was respiratory distress (p = 0.002), and the fourth significant variable was the IV-VC groups (p = 0.017). The mortality risk of those in the LDVC group was 10.2 times low compared to the control group. Similarly, the risk of mortality in the HDVC group was 6.5 times lower than that of the control group. <bold>Conclusion: </bold>Especially low and continious doses of IV-VC suggest fewer days of in-hospital LOS and survival benefit in hospitalized patients with moderate and severe COVID-19. Logistic regression analysis revealed that high-dose VC supplementation also had a mortality-reducing effect.