Background Patients with atrophic gastritis are at risk of vitamin B12 deficiency due to insufficient secretion of intrinsic factors and gastric acid. There have been no studies investigating the vitamin B12 deficiency in patients with atrophic gastritis according to the Kimura-Takemoto classification as well as the association between endoscopic severity of atrophic gastritis and serum vitamin B12 levels.

Methods Cross-sectional study on outpatients visiting the gastroenterology clinic at Tam Anh General Hospital in Ho Chi Minh City from January 2023 to October 2023. Patients with atrophic gastritis on endoscopy would have serum vitamin B12 level tests.

Results There were 78 patients included in the study. The blood vitamin B12 concentration average was 728.12 pg/ml. While the lowest vitamin B12 blood level was 182 pg/ml, its highest value was 1911 pg/ml. Not any patient in our study showed a vitamin B12 blood level lower than 150 pg/ml. There were 7 patients (9%) with B12 blood levels in the low normal range (150-399 pg/ml). There was no association between the concentration of serum vitamin B12 and the severity of gastritis on endoscopy according to the Kimura-Takemoto classification.

Conclusions The prevalence of serum vitamin B12 deficiency in patients with atrophic gastritis on endoscopy was very low. There was no association between the concentration of serum vitamin B12 level and the severity of atrophic gastritis according to the Kimura-Takemoto classification.