Can you increase the quality of haemoglobins?

[Raa]

Is it possible to increase the quality of haemoglobins by using a certain substance, not just 'a healthy diet' or the sort?

[JackBean]

what exactly is your aim? Increase oxygen transport capacity of your blood? Or get as much oxygen from air as possible?
Increasing "quality" of Hb is rather molecular-biological thing.