I don't think Dr. want to say anything about supplements. Out of their areas of expertise I guess. My husband, dx 12/08, GBM takes fish oil. health food store-mercury free, highest you can get, cant really overdue unless on a blood thinner. If so check with Dr. first. He also is taking D3, 2000 mg. daily, a good probiotic to keep his stomach healthy- also health food store. Maitake, Reishi, shitake mushrooms-(capsule in hot water extracts). He also takes a standard men's one a day. We asked his NO about all of these and he said nothing is counterindicated but that the one a day should be the low dose like regular one a days in the pharmacy -no mega doses. Also quercetin, which helps with swelling too. Most of the health food stores sales staff are helpful but worth double checking with the Ben Williams info. Hope this helps, God bless you and your brother. He is blessed to have you looking out for him. Every bit of support helps.
Hug, Donna, Rob's Wife