Abstract
INTRODUCTION: Community-acquired pneumonia (CAP) is a leading cause of hospitalisation and is associated with a high mortality. Vitamin C is a powerful antioxidant and has been used in treatment of infections; however, its role as an adjunctive treatment in CAP is unclear. This review aims to assess the efficacy and safety of vitamin C in adults who require hospitalisation for CAP. METHODS AND ANALYSES: Searches will be conducted from inception to November 2023 on Ovid MEDLINE Daily and MEDLINE, Embase CINAHL, the Cochrane Central Register of Controlled Trials, Scopus, Web of Science and ClinicalTrials.gov databases with the aid of a medical librarian. We will include data from randomised controlled trials reporting vitamin C supplementation in patients with CAP requiring hospitalisation. Two independent reviewers will select studies, extract data and will assess the risk of bias by use of the Risk of Bias tool. The overall certainty of evidence will be assessed by use of the Grading of Recommendations Assessment, Development and Evaluation framework. Random-effects meta-analyses will be conducted, and effect measures will be reported as relative risks with 95% CIs. ETHICS AND DISSEMINATION: No previous ethical approval is required for this review. The findings of this review will be submitted to a scientific journal and presented at an international medical conference. PROSPERO REGISTRATION NUMBER: 483860.