Review Question - QID 109994

A 2-year-old boy is brought to the pediatrician by his mother because she is concerned that her son has not been growing as rapidly as her other children. They recently immigrated to the United States, and she is concerned that his diet in America has not been meeting his nutritional needs. Since immigrating, they have been living in an old house with several of their relatives. On presentation, his temperature is 98.7°F (37°C), blood pressure is 114/62 mmHg, pulse is 118/min, and respirations are 24/min. Based on clinical suspicion, a panel of labs are obtained as follows:

Hemoglobin: 10.2 g/dL
Hematocrit: 30.5%
Mean corpuscular volume: 71 um^3

A peripheral blood smear is also obtained and the results are shown in Figure A. Radiographs show an enlarged skull and prominent cheek bones. No radiodense lesions are seen in this patient. Which of the following treatments would most likely improve symptoms in this patient?