A 68-year-old man presents to his family doctor with nocturia and progressive fatigue. Laboratory tests show haemoglobin 92 g/L, mean corpuscular volume 70 fL, ferritin 8 µg/L, and transferrin saturation 8 percent. He has no overt gastrointestinal symptoms. According to best practice in Canada, what is the most appropriate next step in his management?