This is Cathcart: https://omarchives.org/dr-robert-cathcart-md-a-unique-function-of-vitamin-c/ “In 1970 I noted an increasing bowel tolerance to oral ascorbic acid with illness. In 1984 I wrote, (19) "Based on my experience with over 11,000 patients during the past 14 years, it has been my consistent observation that the amount of ascorbic acid dissolved in water which a patient, tolerant to ascorbic acid, can ingest orally without producing diarrhea, increases considerably somewhat proportionately with the "toxicity" of his illness. A person who can tolerate orally 10 to 15 grams of ascorbic acid per 24 hours when well, might be able to tolerate 30 to 60 grams per 24 hours if he has a mild cold, 100 grams with a severe cold, 150 grams with influenza, and 200 grams per 24 hours with mononucleosis or viral pneumonia. The clinical symptoms of these diseases and other conditions previously described, are markedly ameliorated only as bowel tolerance dose levels (the amount that almost, but not quite, causes diarrhea) are approached (184.108.40.206.24.25)." So, this is back in 1970. His observation was *bowel tolerance* - ie your bowel not trying to shit out as fast as possible excess vitamin C when you are sick. I don’t know if a serum vitamin C was available then. It is now, but not that cheap I think. A problem I think people agree more or less on is it can be hard to know what is happening when you lack blood level data and even more pertinent, tissue delivery, particularly in this case to the lungs. But that’s what Cathcart had in the 1970s. Do you think this is good enough? https://beckibaumgartner.com/wp-content/uploads/2019/05/Cathcart-Vitamin-C-Paper.pdf I can’t find anything placebo controlled by Cathcart (yet, still looking) However I found two trials for sepsis/ARDS published in the last 2 years in JAMA which failed to find evidence of any beneficial change with megadose vitamin C infusion versus placebo, except in all cause mortality as a secondary endpoint in one trial.