Community acquired pneumonia (CAP) is a major cause of illness and death. There is mounting evidence that vitamin C supplementation improves outcomes from life-threatening infections, including pneumonia. During the acute phase of infection there is an increased demand for vitamin C and a high risk of developing deficiency, which may reduce the patients’ ability to fight infection. This proposal will assess the feasibility of conducting a randomised, double-blind, placebo-controlled trial of vitamin C therapy compared with conventional treatment, on the mortality of adults hospitalised with CAP. We will also determine the recruitment rate of patients to the study and recovery rates. The study design can be readily upscaled to a full trial and the pragmatic study design, using a combination of intravenous and oral therapy, will ensure it can be quickly and easily translated into clinical practice if proven beneficial.