Try searching for information on mega doses of vitamin C (or any vitamin in general), and you’ll likely find plenty of the usual stuff and news articles about the dangers of taking supplemental vitamins, of the importance of sticking to the RDA and simply focusing on eating well…
And most of it is pure B.S. — The same type of resistance Linus Pauling had to face as one of the first and biggest advocates of vitamin C therapy. Vitamin therapy can be extremely helpful for a variety of ailments.
It’s not hard to find real, useful information on the topic if you know where to look. I’d start with doctoryourself.com (Andrew Saul’s website). That Vitamin Movie is also a great documentary to watch.
On a personal level, vitamin C (at around 50000-60000mg a day orally) probably saved my life. It was the only thing which allowed me to breathe and ultimately recover from hantavirus. I think it can be a very potent remedy in critical situations, especially intravenously.