A 60-year-old man presents with a 6-month history of increasing fatigue. Physical examination reveals marked pallor, and a CBC shows a macrocytic anemia. Which of the following is the most likely cause of anemia in this patient?

- Macrocytic anemia can be caused by folate & Vit B12 deficiency. - Conditions associated with their deficiency are: Malnutrition - Alcoholics, vegans etc Decreased intrinsic factor, pancreatic & ileal diseases. Fish tape worm infection. Blind loop syndrome Increased requirement like children, pregnancy, lactation etc Drugs like methotrexate, OCP etc -Interfere with Folate metabolism - As the question states an elderly man with malnutrition, most appropriate cause of macrocytic anemia is chronic alcoholism. - Remaining options - Chronic diseases, iron deficiency & renal diseases may present with microcytic anemia not macrocytic.