One of the reasons we understand vitamin C to be essential was from research by Linus Pauling. In the 1970s, Pauling published a study 'Vitamin C and the Common Cold', which brought this critical vitamin to the public attention.
One important aspect of vitamin C, is that 1) the body uses vitamin C with the bodies enzymes to fight disease, and 2) the body can not produce or store this vitamin - ie, we need to consume vitamin C through our diet, and what we don't use is eliminated.
Pauling published 2 studies indicating that allegedly terminal cancer patients were surviving 4 times longer than expected with high doses of intravenous vitamin C.
But probably his most interesting, and controversial findings, was the impact of high doses of vitamin C in fighting cancer. Pauling published 2 studies indicating that allegedly terminal cancer patients were surviving 4 times longer than expected with high doses of intravenous vitamin C.
These were considered controversial because others have tried to test the findings, without being able to reproduce the results. That said, in many countries (like Japan), vitamin C is administered alongside chemotherapy to enhance the effectiveness and improve outcomes.
I strongly recommend you read more about the extensive research and findings at the Linus Pauling Institute as it relates to cancer. There's detailed information about vitamin C's role in immunity.
Two Breast Cancer studies showed a 39%-63% reduced risk of cancer associated with increased daily does of vitamin C.
Colon cancer was shown in a study to be reduced by 19% with combined vitamin C via diet and supplements.
There are additional studies showing vitamin C administered to enhance other therapies.
Fascinating to read, and worth following to learn more as research continues.