Can teeth stains due to a vitamin deficiency be removed?

Yes and no: If the stains are very light, then simple bleaching can improve, but not completly get rid of the problem. If the stains are really dark and noticible, then you need some kind of veneer to cover them.

Depends: It depends on how deep the stains are, if that happened during the developing of the teeth or it happened later in life. Bleaching can take off superficial stains . But in deep internal stains , you might consider other alternatives like veneers.