Vitamin C (ascorbic acid) has some scientific basis for its use in supporting the management of gastritis, particularly in the context of Helicobacter pylori infection-related gastritis. Several studies have suggested that vitamin C can play a role in gastric mucosal protection due to its antioxidant properties, which help neutralize reactive oxygen species and reduce oxidative stress in the gastric lining. Additionally, vitamin C may inhibit the growth of H. pylori and enhance the efficacy of conventional eradication regimens, as lower gastric levels of ascorbic acid have been observed in individuals with gastritis and H. pylori infection.

However, the overall quality and quantity of clinical evidence remain limited. Some randomized controlled trials and meta-analyses have shown modest benefits of vitamin C supplementation as an adjunct to standard H. pylori eradication therapy, such as increased eradication rates. Yet, these findings are not consistent across all studies, and the benefit appears to be relatively modest. There is less evidence to support vitamin C use for gastritis not associated with H. pylori. No major gastroenterological guidelines currently endorse vitamin C as a primary treatment for gastritis.

In summary, vitamin C has a plausible scientific rationale and some supporting evidence for adjunctive use in H. pylori-related gastritis, but its overall effectiveness is not strongly established, and further research is needed.