There are a number of posts all over the internet on this topic, however none of them have been able to isolate and solve the problem.
I am trying to show some special U
It works on your Mac because the font used by your mac contains those special characters. It would be impossible to create a fontfile that contains all characters defined in unicode. Chinese fonts are a good example: none of them contain all of the ~60.000 known Chinese characters because the font file would be huge and unusable.
You could try using the font from your Mac on android (might be copyright issues - try finding a free font that contains the characters: package the (ttf) file in your application, for example in the /assets folder, and then in your application load that font with
TypeFace typeFace = Typeface.createFromAsset(assetmanager,"fontfile.ttf");
You can then use this in a TextView like so:
TextView view = (TextView) findById(R.id.mytext);
view.setTypeFace(typeFace);