Mel, welcome to the forum! I know some liver patients have benefited from taking milk thistle. While everyone seems to be touting Omega 3s these days, I don't know how safe they are for someone with liver disease. I do not have AIH (have hep C and cirrhosis), but we do have some members here with AIH who hopefully will post a response to you. All supplements, vitamins, etc., should be cleared through your hepatologist prior to taking them, as they might be contraindicated in your particular case.
Again, welcome!