 Studies in the 70s showed an extraordinary survival gain in terminal cancer patients with vitamin C, a simple, relatively non-toxic therapy, and so no wonder it got a lot of attention, especially when reported by world-renowned scientist Linus Pauling. But studies like this in the 1980s found no such benefit, and so, alas, they were left with the inevitable conclusion that the apparent positive results in the original study were the product of bias rather than treatment effectiveness. In the 1990s, though, an alternative explanation arose. The disappointing 80s research only used oral vitamin C, whereas the apparently successful 70s experiments also gave vitamin C intravenously, and we didn't realize until the 90s that the same dose given IV can lead to dramatically higher levels in the bloodstream than have taken orally. So maybe high-dose vitamin C does help in terminal cancer, but maybe only when given intravenously. Encouraging case reports continued to be published. Here there was a regression, remission, and cured document in an individual case of advanced kidney cancer, bladder cancer, and lymphoma. But that's three success stories out of how many. I mean, if it was 3 out of 100 or even 3 out of 1,000, well, okay, if the treatment is sufficiently non-toxic. But there's evidence that IV vitamin C is widely used in the alternative medicine world, as in 86% of practitioners serve it. Just those 172 practitioners alone treated about 10,000 patients a year. And you ask the manufacturers, and they're selling hundreds of thousands of vials of the stuff in the US. Now it's not all being used for cancer, but presumably at least thousands of cancer patients are being treated every year with IV vitamin C, making the publication of three remarkable case reports seem less impressive. So no matter how amazing these cases seemed, it's possible the cancer's just spontaneously regressed all on their own and was just a coincidence that happened after they were given vitamin C. For sure you have to put it to the test. To date there's been some small pilot studies, and the results so far have been disappointing. The good news is that even insane doses of IV vitamin C seem remarkably safe, but failed in the study of 2,000 patients to demonstrate anti-cancer activity. Similar small studies have been published all the way through to the present with tantalizing but inconclusive results. What we do know is that the present state of cancer treatment is unsatisfactory. People have this perception that chemotherapy will significantly enhance their chances for a cure, but put all our cancer killing chemo together, and the overall contribution to five-year survival is on the order of 2%. All those side effects for 2.1%. At a cost of maybe $100,000 per patient per year. So it may be worth looking deeper into therapies like IV vitamin C. However, the lack of financial reward, since vitamin C can't be patented and sold for $100,000, and bias against alternative medicine could dissuade conventional investigators and funding agencies from seriously considering this approach. So decades later, what can we conclude? After trials which have included at least 1,600 patients over 33 years, we have to conclude that we still don't know whether vitamin C is any clinically significant anti-tumor activity. Although there is currently no definitive evidence of benefit, the Mayo Clinic randomized controlled trials did not negate the potential benefit based on what we now know about the oral versus IV roots of administration. So we're kind of back to square one. Does it work or not? There are highly polarized views on both sides, but everyone's working off the same incomplete data. What we need are carefully controlled clinical trials. The question is, what do we do until then? If it was completely non-toxic, then we wouldn't argue, well, buddy, you've got to lose, but it's not. It's only relatively non-toxic. For example, there have been rare but serious cases of kidney injury reported. I mean, after all, if it's so safe, why did our bodies evolve to so tightly control against excess absorption? It can also be expensive and time-consuming. Infusion costs $1 to $200 out of pocket, since insurance doesn't pay for them, which can be quite a boon for alternative medicine practitioners. About 90% of the millions of doses of vitamin C being dispensed are in for-profit arrangements. So there's financial pressures pushing in both directions for and against this treatment. Given the relative safety and expense, though, controlled studies even find a small benefit it would be worthwhile. And if they don't, okay, fine. The vitamin C question can be put to rest once and for all. But in cancer treatment, we don't have the luxury of jettisoning possibly effective, relatively non-toxic treatments. We should revisit promising avenues without prejudice and with open minds.