A 70-year-old man is referred for further evaluation by his primary care practitioner, following the detection of anemia in a complete blood count. His only complaints are worsening fatigability and exertional dyspnea for six months.

His medical history is positive for essential hypertension for five years and type 2 diabetes mellitus for one year, both of which are uncomplicated, and well-controlled via diet and exercise alone. He is not on any medications currently. His surgical and family histories are unremarkable.

His diet is nutritionally balanced, containing meat, fish, and vegetables. He only drinks socially and aside from very short-term experimentation in his youth, has not smoked. There is no history of allergies.