Studies in the 1970s showed an extraordinary survival gain in terminal cancer patients with vitamin C, a “simple and relatively nontoxic therapy.” It’s no wonder it got a lot of attention, especially when reported by a world-renowned scientist, Linus Pauling. But studies in the 1980s found no such benefit, so scientists were “left with the inevitable conclusion that the apparent positive results [in the original study] were the product of case-selection 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 intravenously can lead to dramatically higher levels in the bloodstream than when taken orally. So maybe high dose vitamin C does help in terminal cancer, but maybe only when given intravenously. This is the topic of discussion in my video The Role of Vitamin C in the Treatment of Terminal Cancer.

Encouraging case reports continued to be published. Regression, remission, and cure had been documented in individual cases of advanced kidney cancer, bladder cancer, and lymphoma, but that was three success stories out of how many? If it was three out of a hundred, or even three out of a thousand, then okay, if the treatment is sufficiently nontoxic. But there is evidence that IV vitamin C is widely used in the alternative medicine world, as in 86 percent of 172 practitioners surveyed. Just those 172 practitioners alone treated about 10,000 patients a year, and manufacturers are selling hundreds of thousands of vials of this stuff in the United States. 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 cancers just spontaneously regressed all on their own, and it was just a coincidence that it happened after the patients were given vitamin C. To know for sure, you have to put it to the test.

To date, there have 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 a study of two dozen patients “to demonstrate anticancer activity.” Similar small studies have been published, all the way through to the present, with results that are tantalizing but inconclusive. What we do know is that the present state of cancer chemotherapy is “unsatisfactory.” People have a perception that chemotherapy “will significantly enhance their chances of cure,” but if you put all our cancer-killing chemo together, the overall contribution to five-year survival is on the order of 2 percent—all those side effects for a 2.1 percent survival rate bump, 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 1,609 patients over 33 years, we have to conclude that we still do not know whether Vitamin C has any clinically significant antitumor activity.” Although “there is currently no definitive evidence” of benefit, the Mayo Clinic’s randomized controlled trials “do not negate the potential benefit” based on what we now know about oral-versus-IV routes of administration. So, we’re kind of back at 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, though, is what do we do until then?

If it was completely nontoxic, one could argue, “Well, what have you got to lose?” But it is not—it’s only relatively nontoxic. For example, there have been rare but serious cases of kidney injury reported. 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. Each infusion can cost $100 to $200 out of pocket since insurance doesn’t pay for it, which can be quite a boon for alternative medicine practitioners. About 90 percent of the millions of doses of vitamin C being dispensed are in for-profit arrangements, so there are financial pressures pushing in both directions, for and against this treatment.

Given the relative safety and expense, though, if controlled studies even find a small benefit, it would be considered worthwhile. And if they don’t, the vitamin C question can be put to rest once and for all. But “[i]n cancer treatment we currently do not have the luxury of jettisoning possibly effective and nontoxic treatments. We should revisit promising avenues, without prejudice and with open minds…”

This video is the third installment in a three-part series. For the complete saga, watch the other two videos Intravenous Vitamin C for Terminal Cancer Patients and Vitamin C Supplements for Terminal Cancer Patients.

I discuss the conundrum of what do to about funding research of non-patentable natural treatments in Plants as Intellectual Property: Patently Wrong?.

Additional videos of interest include:

In health,

Michael Greger, M.D.