What is a common cause of anemia in patients with chronic renal failure (CRF)?

In patients with chronic renal failure (CRF), a common cause of anemia is the reduction or complete cessation of erythropoietin production. Erythropoietin is a hormone primarily produced by the kidneys that stimulates the bone marrow to produce red blood cells. In CRF, the kidneys are damaged and unable to produce adequate levels of erythropoietin, leading to insufficient red blood cell production, thereby causing anemia. This is particularly prevalent in patients with advanced stages of renal failure where kidney function is severely compromised.

The other options do not align with the pathophysiology of anemia in CRF. Excess production of erythropoietin would not be a factor, as the damage to the kidneys typically causes decreased production. Increased iron absorption is not typically observed in CRF; rather, patients often have challenges with iron utilization due to inadequate dietary intake or impaired erythropoiesis. Autoimmune disorders can contribute to anemic conditions but are not the primary cause of anemia specifically associated with chronic renal failure. Thus, the lack of sufficient erythropoietin is the main contributing factor to anemia in patients with chronic renal failure.