We all know darn well the RDA is a joke. It has been shown over and over.
http://www.vitamincfoundation.org/vitcrda.htm
Vitamin C has long been a politically loaded subject in US medical circles, especially after the late Dr. Linus Pauling had the gall to pronounce that it was effective in decreasing the severity and duration of the common cold. Pauling’s 1971 meta-analysis of the then-published studies was published in the Proceedings of the National Academy of Sciences and concluded that vitamin C significantly lessened cold-related illness (P.00003). Although a P value less than 0.05 is considered significant and a P value less than 0.001 is considered outstanding, few physicians accepted Pauling’s analysis.
The medical community’s resistance to Pauling’s conclusion soon found a champion in Robert Chalmers, who, in 1975, published his own meta-analysis of “reasonably well controlled” studies in which he concluded that vitamin C only decreased colds by 0.11 days, a “minor and insignificant” matter.
The fact that Chalmers’ analysis flatly contradicted Pauling’s resulted in it being highly cited in the medical literature — more than twice as often to date. This discrepancy is especially telling because Chalmers’ analysis was more superficial and made numerous errors reporting on the results of studies considered in his analysis. Just how many errors was not clear until recently when Harri Hemilä of the University of Helsinki and Zelek Herman of the Linus Pauling Institute published a retrospective analysis of Chalmers’ review citing an appalling number of mistakes, almost all of which were prejudicial against vitamin C. Replacing Chalmers’ flawed data with correct data resulted in a finding of 0.93 fewer days of illness (P.01), a 21% savings in sick time (P.001) and a combined P value from the six statistically significant studies of less than 0.000004 (2-tailed probability of difference). In other words, Linus Pauling was right. Vitamin C does, in fact, decrease both the duration and severity of colds. And studies conducted after Pauling’s and Chalmers’ meta-analyses have born this out.
Why were so many scientists on the wrong side of this matter? The answer is simple: politics! Medical attitudes against vitamins were strident in the 1970s, despite a considerable volume of evidence indicating their effectiveness. In the 1990s, the anti-vitamin rhetoric is still alive, but it is being toned down to a large degree by the volume of young professionals entering science and medicine who know beyond a shadow of a doubt that their older peers are just plain wrong.
http://www.ceri.com/ed-vitc.htm
After seeing an ER attending physician recommend Vitamin C supplements for an upper respiratory illness, URI, aka the common cold, I probably did a few days worth of research on the topic on what was probably then called MedLine at the time. This is what I recall about Vitamin C supplementation:
Pharmacologic doses, as opposed to physiologic doses, on a routine basis only helped patients with an absolute vitamin C deficiency, aka scurvy. It had no effect on the the incidence of URI or other illness.
Pharmacologic doses decreased the incidence of flu-like illness suffered by runners of marathons compared to those runners who took only placebos.
Pharmacologic doses decreased the duration of symptoms of those with URIs.
I use and recommend Vitamin C when I have a cold.
IMHO, Vitamin C supplementation with pharmacologic doses only seems to be good advice when a person or animal has certain abnormal stressors. I would be leary of what you find on PubMed if the results have not yet been replicated, even more so about what you find unsolicited, and linked on the Internet.
Here's the search strategy that I used to find that citation on PubMed. (flu-like illness or influenza or URI or upper respiratory illness or viral syndrome or stress) and (vitamin C supplementation or ascorbic acid supplementation)
Click on "Related Articles", near to the right of the title, and you'll find a bunch of articles about anti-oxidants with contradictory results. Caveat emptor.
Thank you. I know from experience of the benefits of Vit C. They'll never convince me otherwise.
Speaking of politics; http://www.ceri.com/trypto.htm