The Effects of Vitamin C in Patients with Chronic Obstructive Pulmonary Disease: A Systematic Review of Clinical Trials

The present systematic review aimed to investigate the effects of vitamin C on the improvement of chronic obstructive pulmonary disease (COPD). Online databases (PubMed, Scopus, Embase, Cochrane Library and Web of Sciences) were systematically searched to find clinical trials evaluating the effects of vitamin C supplementation on COPD up to July 2019. After excluding irrelevant records, 3 studies were included. Two included studies demonstrated significant effect of vitamin C supplementation on COPD improvement, but another study did not. In conclusion, vitamin C might have positive effects on COPD patients. But more future studies are needed to reach a definite conclusion.