AKT-2893

A 59-year-old woman has been experiencing fatigue and difficulty breathing. She follows a lacto-vegetarian diet and takes ramipril and indapamide for high blood pressure. Upon examination, she appears pale and has glossitis, but no neurological symptoms. Her blood test results show a low hemoglobin level, low white blood cell count, low platelet count, high mean corpuscular volume, and the presence of oval macrocytes, hypersegmented neutrophils, and circulating megaloblasts. Her ferritin level is within normal range, but her serum folate and vitamin B12 levels are low. What is the most likely cause of her symptoms?