USMLE (United States Medical Licensing Examination) Practice Exam 37

A 26-year-old woman comes to the clinic because of fatigue and lightheadedness for 2 months. She follows a strict vegan diet. She takes no medications. Vital signs are normal. Physical examination shows pale conjunctivae. Laboratory studies show: hemoglobin 9.2 g/dL, mean corpuscular volume 72 fL, ferritin 8 ng/mL (reference 15–150), and reticulocyte count 0.6%. Which of the following is the most likely physiologic response in the kidney to this patient’s anemia?