Megaloblastic Macrocytic Anemias By Gloria F Gerber, MD, Johns Hopkins School of Medicine, Division of Hematology Reviewed / Revised Jun 2023 View Patient Education Etiology Pathophysiology Symptoms and Signs Diagnosis Treatment Key Points Topic Resources Macrocytosis in Liver Disease Oval Macrocytes and Hypersegmente... Megaloblastic anemias result most often from deficiencies of vitamin B12 and folate.