A 72-year-old male with stage 4 chronic kidney disease (eGFR 18 mL/min) presents to the clinic reporting progressive fatigue and exertional dyspnea over the past two months. His laboratory results show hemoglobin 8.2 g/dL, hematocrit 25%, reticulocyte count 0.4%, serum iron 55 mcg/dL, and ferritin 320 ng/mL. He denies any visible blood in his stool and has no history of dietary deficiencies. Which finding best explains the primary mechanism responsible for this client's anemia?
- Chronic blood loss from uremic platelet dysfunction
- Folate deficiency caused by urinary wasting of water-soluble vitamins
- Decreased intestinal iron absorption due to elevated hepcidin levels
- Insufficient erythropoietin production by the damaged kidneys