I know about the Linus Pauling story. It goes to show that even Nobel laureates may get things wrong. A Cochrane database review came to the conclusion that the evidence for Vit C as an effective remedy for colds is, shall we say, flimsy at best. C has some antiviral properties, yes, but they aren't the miracle cure for the common cold. The evidence is contradictory. The authors come to the conclusion (I paraphrase): people who want to try and experiment with C can do it, because there is no harm, but shouldn't expect too much. Vit C is water soluble, and, as is the case for most water-soluble vitamins, any excess is just excreted. The industry selling the C isn't interested in effects and facts, but their bottom line. So, I don't supplement with it, because Vit C is everywhere, even hidden in foods where you might not suspect it, because it's also an excellent preservative. That's why hypovitaminoses of C are extremely rare in our 'developed' societies.