Combined B12 and iron deficiency revealing pernicious anemia: A case report

Pernicious anemia (PA) is the most common cause of Vitamin B12 deficiency in the West. However, dietary insufficiency is the leading cause of B12 deficiency in India. PA is an autoimmune disorder characterized by autoimmune destruction of gastric parietal cells. The classical triad is megaloblastic anemia, autoimmune gastritis, and positive antibody testing. Concomitant iron deficiency is common in 50% of patients and can delay or mask B12 deficiency. We report a case of recurrent B12 deficiency in a vegetarian with subsequent iron deficiency leading to the diagnosis of PA. Laboratory evaluation demonstrated severe Vitamin B12 deficiency (<100 pg/mL), followed 1 year later by iron deficiency (ferritin 11.4 ng/mL; transferrin saturation 4.4%) and Vitamin B12 deficiency. Anti-parietal cell antibody was strongly positive, supporting the diagnosis of PA.