<prompt> Anemia in chronic renal failure CRF is due to -Decreased erythropoietin productionIron deficiencyHypoplastic bone marrowDecreased Vit - B12  <response>: Erythropoietic activity in the body is regulated by erythropoietin.The principle site of production of erythropoietin is the kidney .Decreased production of erythropoietin by diseased kidney in chronic renal failure results in decline in erythropoiesis anemia.Reference :Harsh mohan textbook of pathology sixth edition pg no 655. 