Therapeutic effects of high-dose vitamin C supplementation in patients with COVID-19: a meta-analysis

Context Coronavirus disease 2019 (COVID-19) could induce the cytokine storm due to overactivation of immune system and accompanied by acute respiratory distress syndrome as a serious complication. Vitamin C has been effective in improving lung function of patients by reducing inflammation.Objective The aim was to explore the therapeutic effects of high-dose vitamin C supplementation for patients with COVID-19 using meta-analysis.Data Sources Published studies were searched from PubMed, Cochrane Library, Web of Science, EMBASE, and China National Knowledge Infrastructure databases up to August 2022 using the terms vitamin C and COVID-19. Data analyses were performed independently by 2 researchers using the PRISMA guidelines.Data Extraction Heterogeneity between the included studies was assessed using I2 statistics. When I2 & GE;50%, the random-effects model was used; otherwise, a fixed-effects model was applied. Stata 14.0 software was used to pool data by standardized mean differences (SMDs) with 95% CIs or odds ratios (ORs) with 95% CIs.Data Analysis The 14 studies had a total of 751 patients and 1583 control participants in 7 randomized controlled trials and 7 retrospective studies. The vitamin C supplement significantly increased ferritin (SMD = 0.272; 95% CI: 0.059 to 0.485; P = 0.012) and lymphocyte count levels (SMD = 0.376; 95% CI: 0.153 to 0.599; P = 0.001) in patients with COVID-19. Patients administered vitamin C in the length of intensive care unit staying (SMD = 0.226; 95% CI: 0.073 to 0.379; P = 0.004). Intake of vitamin C prominently alleviate disease aggravation (OR = 0.344, 95%CI: 0.135 to 0.873, P = 0.025).Conclusions High-dose vitamin C supplementation can alleviate inflammatory response and hinder the aggravation of COVID-19.

Automated summary

This meta-analysis explored the therapeutic effects of high-dose vitamin C supplementation for patients with COVID-19, and the results showed that it can alleviate inflammatory response and hinder the aggravation of the disease.