While it is easy to criticize any animal model study, especially when targeting cancer, we should be HIGHLY skeptical of any mouse study that uses vitamin C. Why?
Mice synthesize their own vitamin C; humans do not (hence, it should properly be called ascorbic acid in mice, not vitamin c). The biological pathways involving this compound are very different between species, and deserve special consideration.
The dose makes the poison (or the cure). According to the article they gave daily injections containing 300 oranges worth of vitamin C (which google tells me is over 15 grams of vitamin C, an order of magnitude larger than the daily recommended dose for adult humans).
Certainly being skeptical is still warranted, as OP is correct, there are significant differences in how this particular compound is handled species to species. However, simply that mice produce ascorbic acid does not imply that they produce it in quantity great enough to impact this kind of tumor.
No of course not. It does mean that this particular pathway is very different in the mouse model, and studies of vitamin C and mice should be taken with an extra grain of salt.
In this regard, I think we agree very much! I simply wanted to point out that the specific example that they endogenously synthesize ascorbic acid wasn't a great reason for why this particular trial wouldn't be valid.
Be skeptical of any scientific claim made, especially around possible links between animal models and human clinical environment, and even more especially when the systems involved are not highly conserved cross species.
Mega-dosing vitamin C is fairly common among alternative medicine practitioners. The medical community recommends an upper limit of 2g per day for adults due to mild laxative effects around that dosage. There's a paucity of trials that experiment with dosages above that level, so long term effects are mostly unknown.
I experimented 5+ years with it and took on several occasions 100+g per day with regular input between 10-15g per day.
The only problem I had after 5 years is slight pain in esophagus immediately after taking C, but it passed after I switched to taking C on full stomach.
Note: you MUST use pure AA powder, nothing else. Timing of C is essential - you must do it right, or the effects are minimal (you basically have to simulate the liver ancestral production now disabled in humans).
Vitamin C is a miracle thing IMO, especially 4 kids. My daughter was taking 1g since age 1 (now has 5) and she has remarkable health (she is sick once or twice per year for 2-4 days without any complications with being in kindergarten with 30+ kids since age 1, although the non-vitamin-c factors are contributing to this picture quite a bit).
Vitamin C is the most effective virus killer in large doses if you time it right. It is poor antibiotic but you have many options in plant world for that.
These are fairly typical anecdotal comments made by people pushing Vitamin C cures / treatment, often in conjunction with mention of 'miracles'. Oblig xkcd:
https://xkcd.com/1217/
What can I say, it works for me and few more people I know.
But the argument you are giving is quite pointless - vitamin C has no side effects and it is dead cheap so there is no harm in trying it out for several months and deciding on your own if its good or not for you.
I didnt want to elaborate here, i did so on several other places. It basically stops common cold and probably other common viral diseases in a day if used right.
I'm not aware of evidence that this is true for megadoses (e.g. 10g per day, as you mentioned).
Given that you are making a claim not supported by mainstream medical consensus (that megadoses of vitamin C have positive health effects), you are essentially arguing that megadoses of Vitamin C have a different effect than regular doses. Given that you admit that megadoses have a different effect to regular doses, what is your evidence that megadoses have no side effects?
Toxicity of vit-c is very low. Death by vit-c overdose is un-heard of. Intaking enough vit-c to cause death, could be due to sheer weight of substance intaken rather than bio-chemical function of vit-c.
https://en.wikipedia.org/wiki/Vitamin_C#Overdose
Also studies conducted on animals (especially primates) that cannot synthesize vit-c on their own, show that they intake about upto 80x the RDA value of vitamin-c. So, humans intake as low as 1.25% of vit-c levels that monkeys eat.
https://en.wikipedia.org/wiki/Vitamin_C#Daily_requirements
Most often than not, RDA values are a joke and should be treated as bare minimum levels to prevent diseases such as scurvy and not as the optimum level. Sub-clinical deficiency in essential vitamins and minerals always happen.
> Do you have any comprehensive resource on timing Vit-C supplements?
There isn't any that I am aware of except bowel tolerance method. IMO, timing during healthy state is relaxed - twice per day is probably enough for most people; during stress however individual dose shouldn't be higher but should be taken more frequently (until bowel starts to complain, which means C is not absorbed any more and passes to colon where it causes diarrhea trough osmosis). What is remarkable here is the difference between bowel tolerance in healthy (low) and disease (high) state which suggests that vitamin C absorption increases.
> Also what form of supplement & which brand did you intake? Liposomal vit-c?
I take pure synthetic AA with sodium bicarbonate half of the time (3-5g x2). I don't have experience with liposomal vit-c but I am sure it is way better then regular C, altho far more expensive.
> Do you also have any comprehensive resources that explains if vit-c supplements can affect recovery from lifting weights or general exercise?
I don't have one at hand now. Some people think it prevents adaptation during exercise and don't take it. I personaly think it reduces stress so it simply gives you an option to work more. Since exercise can actually reduce your immune system if you overdo it or have concurrent stressor, AA intake will certainly be more beneficial on the long run then any supposed adaptation shortcomings.
You have not established causation. That is, you and others you know do it; you have a health outcome you are comfortable with; yet you have not established causation between the two.
Ironically, you're talking about the very thing this article leads with: that Linus Pauling touted vitamin C as a miracle cure with over-dosing, despite no evidence, and none has been found.
(I also think that article lead is irresponsible, because if it turns out this study holds up, and vitamin C is a viable treatment for this kind of cancer, we have soundly shown it does not work in the many areas we have tested it.)
What do you deem "insignificant"? The required daily dose is about 90 mg. There are experiments which include several grams [1, 2, 3], which is a large enough dose that those writing the papers call it a "megadose". If you consider a megadose to be 1,000g and 10,000g, then I think that's just moving the goal posts. Is there a dosage level at which you would say, "Yes, with no clear signal at that level, it's probable it makes no difference"?
[3] http://www.ncbi.nlm.nih.gov/pubmed/8191227, shows some positive evidence, which may be noise, and concludes "needs more research" - despite there already being a lot, with no clear positive signal.
Mice synthesize their own vitamin C; humans do not (hence, it should properly be called ascorbic acid in mice, not vitamin c). The biological pathways involving this compound are very different between species, and deserve special consideration.