Vitamin B12 deficiency anemia following total gastrectomy

Abstract

Background: Megaloblastic anemia is a hyperchromic macrocytic anemia caused by impaired DNA synthesis and delayed cell division, most commonly resulting from deficiencies of cobalamin and folic acid. Vitamin B12 is obtained from animal-derived foods such as meat, fish, eggs, and dairy products. In the stomach, it is released from dietary proteins by gastric acid and subsequently binds to an intrinsic factor, after which it is absorbed in the distal ileum. Therefore, vitamin B12 deficiency may occur following gastric or intestinal resection surgery. Another common cause of vitamin B12 deficiency is pernicious anemia, which results from autoimmune atrophic gastritis leading to decreased secretion of intrinsic factor. Vitamin B12 deficiency is most frequently observed in individuals over 60 years of age, and its clinical manifestations vary depending on the severity of deficiency. Patients with mild to moderate deficiency commonly present with fatigue, general symptoms of anemia, glossitis, and neurological disturbances. In cases of severe deficiency, profound hematological abnormalities, severe neurological manifestations, and cardiac involvement such as cardiomyopathy may be observed. In this report, we present a clinical case of a 46-year-old male who developed severe vitamin B12 deficiency anemia following total gastrectomy, complicated by anemia-induced mild hypokinesia of the anterior and inferior walls of the heart. Conclusion: If vitamin B12 deficiency–related anemia is accurately diagnosed, appropriately treated, prevented, and monitored starting from the primary health care level, it can have a positive impact on patients’ quality of life. Given that this condition may present with diverse clinical manifestations, a multidisciplinary team approach involving specialists in hematology, neurology, psychiatry, gastroenterology, cardiology, and nutrition enables early identification and prevention of potential complications, thereby improving overall clinical outcomes.