Can a person with anemia and reduced immunity use Metypred?

Good morning. I am writing about the drug Metypred. My dad was at the pulmonologist yesterday and that's exactly what he was prescribed. Unfortunately, the doctor did not look at the results, and Dad has strong anemia and weak immunity. Is it safe? And is it possible to take vitaminS B and D when taking Metypred? How can you raise his immunity?