Likewise, how can you compare chemotherapy to Vitamin C in a double blind study? The chemotherapy group would have intense pain, sickness, their hair will fall out, and so on. The Vitamin C group would have no added pain, no sickness (except perhaps diarrhea), and their hair will not fall out, etc. A double blind study in this case is nonsense. What are you going to do, secretly put Drano (a toxic sludge used in plumbing to clean drain pipes) and ipecac (which makes people vomit) in with the Vitamin C so the Vitamin C group will experience intense pain and sickness and not know which blind group they are in?