In this study it was aimed to detect the incidence of vitamin B12 deficiency due to mucosal injury caused by Helicobacter pylori and to investigate the effects of this deficiency on other systems and especially hematologic system in children. A total of 192 children, 100 female and 92 male, with a mean age of 9.7±2.7 years were included in the study. All these cases in the study group were Helicobacter pylori positive on the basis of C14 breath test and Helicobacter pylori stool antigen test. Serum levels of vitamin B12 were measured twice; before and one month after Helicobacter pylori eradication treatment. Triple drug treatment consisting of clarithromycin, amoxicillin and omeprazole was used for Helicobacter pylori eradication. Patients were reinvestigated after treatment with respect to Helicobacter pylori positivity. Forty children with characteristics similar to Helicobacter pylori positive cases but without Helicobacter pylori positivity were chosen as the control group. Helicobacter pylori was eradicated in 149 (77.6%) of the 192 patients in the study group after treatment. In the study group, serum vitamin B12 levels after Helicobacter pylori eradication were significantly higher than the pretreatment levels (p=0.017). When we compared the pretreatment and posttreatment hematologic parameters of 13 cases with low vitamin B12 levels to those of the 179 cases with normal vitamin B12 levels, there were no statistically significant differences (p>0.05). While these 13 cases with low vitamin B12 levels turned to be Helicobacter pylori negative after treatment, their vitamin B12 levels increased closing to normal levels although no exogenous vitamin B12 was given. In conclusion, Helicobacter pylori infection in children may cause vitamin B12 deficiency, and this deficiency may resolve spontaneously after Helicobacter pylori eradication without any vitamin B12 supplementation.

Keywords: Helicobacter pylori infection, children, vitamin B12