In response to several of your comments above - please let me know if you have follow up questions:
1)
According to the Linus Pauling Institute at Oregon State University, if you are consuming vitamin C orally, whether in food or in supplements, you see 100% absorbtion of the nutrient at doses up to 200mg. Once your dosing exceeds 500 mg, you see fractionally
less absorbtion of any vitamin C you consume past that point. Once vitamin C concentrations in your blood plasma reach max capacity, additional vitamin C is largely excreted in the urine.
This so-called saturation point varies between individuals, but the main takeaway here is that, if you're taking normal vitamin C supplements, you cannot steadily increase the available vitamin C in your body by simply "upping the dose." Past a certain threshold, the body stops absorbing the nutrient, and what you're left with is vitamin-enriched urine.
2) IV administration of vitamin C bypasses this restriction and allows higher doses of the nutrient to be sustained in the blood.
Historically, researchers have proposed that vitamin C supplmentation, in general, could be used to treat pneumonia because the condition is a common complication of scurvy, which results from vitamin C deficiency. Since then there have been anecdotal accounts, case studies, and preliminary clincal trials attempting to use IV vitamin C to treat pneumonia, with mixed or ineffective results
(see here). In other cases, when vitamin C appeared to help somewhat, I've seen that the treatment is sometimes combined with other interventions, so it's difficult to discern the effect of vitamin C in isolation
(see here).
If you have a particular study in mind that you're referencing here, please link it in a comment and I can take a look. But from what I see in the literature, this link between high dose vitamin C and pneumonia remains tenuous at best.
3)
In the context of this study, shared by
@vedhogger, the IV vitamin C they're describing as "high-dose" is only a 50-200mg dose, which seems in line with standard vitamin C supplementation. In addition, In addition, this treatment appears to be recommended only for people with mild symptoms (assuming my Chinese to English translator is accurate). In other words, in this context, it seems as though the treatment team is ensuring that patients receive enough vitamin C to maintain normal immune function.
4) For general reference, the Journal of Orthomolecuar Medicine and the associated Orthomolecular Medicine News Service have been historically dismissed by the scientific community for promoting studies with poor experimental design; sweeping conclusions based on limited evidence; and little clinical relevance. I came across several studies from this journal in my research, read through them and reached the same conclusion as scientists and science journalists before me.
What's more, if you notice on the main orthomolecular.org website, if you click "Contribute," the link will lead you to a website called the Riordan Clinic where you can buy supplements and lab tests of varying sorts. That in and of itself should raise your suspicions as to whether these articles are disseminating the best scientific information available, or are primarily aimed at trying to sell you something.