To the OP, please tell her to start taking cod liver oil (mercury free). Many people nowadays are lacking vita D because they cover up from the sun, wear UV prot. make-up, sunglasses...

Since vita C and vita A work together, this could be her problem.

If I were here, I would take the CLO (cod liver oil) and make sure she is outside at least an hour every day, exposing her skin and eyes to the natural light.