I too am on Mestinon which helps some and have also elected not to take pred (unless it gets real bad) I am checking on something called cellcept but on the Natural Healing bandwagon. Found this interesting article you may want to read

Couldn't post the the link in this response but you can google - Walter Last and Myasthenia and it will come up titled - MYASTHENIA GRAVIS - A Holistic Therapy - By Walter Last

Has the vitamins helped you with symptons? I read manganese (not magnesium) is a good one. Check out the article it details all but no info on dosages Let me know what you think.