Vitamin C reduces interleukin-6 plasma concentration: a systematic review and meta-analysis of randomized clinical trials

SummaryBackground Interleukin 6 is an important biomarker for distinguishing high-risk and low-risk patients, a constituent of the Nutrition Risk in Critically III (NUTRIC) Score. Studies have indicated beneficial effects vitamin C on lowering IL-6 levels reducing cytokine storm. However, there still controversy about exact effect, appropriate route, dose usage. This meta-analysis was conducted to evaluate current evidence base relating intervention decreasing levels. Methods A systematic search performed PubMed, Scopus, Google Scholar, Cochran databases, from database inception July 3rd 2021, obtain any possible randomized clinical trial inclusion. After screening removing unrelated duplicate articles, 24 eligible articles remained statistical analysis. Results We found significant effect supplementation via peroral (PO) (WMD = -0.29 pg/l, 95% CI [-0.42, -0.16], P<0.0001) intravenous (IV) routes with -7.99 [-8.36, -7.62], P<0.0001). Conclusions Vitamin C, at doses 250–1000 mg/day less than one week treatment, regardless route administration, reduces participants.