Colonization of the gastric mucosa with Helicobacter pylori H.p. reduces the vitamin C concentration of gastric juice. Eradication of H.p. within four weeks after completed treatment does not exert a significant effect on changes in the concentration of vitamins A, E and C in gastric juice or serum. Despite this after eradication a rising trend of vitamin E in gastric juice was recorded. Substitution of vitamin C and E in gastritis associated with colonization with H.p. has a favourable effect and may reduce the risk of malignization.