Macrocytic anemia

An anemia characterized by increased mean corpuscular volume (MCV >100 fL) with reduced hemoglobin/hematocrit, due to impaired erythropoiesis producing enlarged erythrocytes. Possible causes are vitamin B12 or folate deficiency, alcohol use, drugs (chemotherapy, anti-seizure medications, HIV treatment), liver disease, hypothyroidism, or marrow disorders such as myelodysplastic syndrome.