I Am Taking 1g Of Mycophenolate For Autoimmune Hepatitis Twice

I am taking 1g of mycophenolate for autoimmune hepatitis twice a day and am currently being treated for ashthma and chest infection. The gp suggestion 3g vit c might help. I am wondering if there is any negative interactions that I should be aware of with these two. Pharmacist said nil, but I am not convinced with her answer as she only did a very quick research (less than 20 secs.) regarding the question. What would be your answer? thank you Julie.