Harri Hemila

Vitamin C was first produced in large amounts from Paprika
Vitamin C was identified in the 1930s by Albert Szent-Györgyi, who received his Nobel Prize partly for this work. He found that paprika is a particularly rich source of the vitamin, which made it possible to produce kilograms of it for research purposes ([1963] Annu Rev Biochem 32: 1–14). Nowadays, the most convenient way to increase vitamin C intake is by way of 500-mg tablets, but further research is needed to explore the conditions in which supplementation may be beneficial.
Papers by and about: Albert Szent-Gyorgyi

Charles King did important research on vitamin C before Szent-Gyorgyi identified it.
Papers by and about: Charles Glenn King

In 1971, Linus Pauling published a meta-analysis of 4 placebo-controlled trials in which at least 0.1 g/day of vitamin C was administered regularly to the study group. Pauling concluded that there was strong evidence that vitamin C decreased ‘integrated morbidity’ due to colds (P = 0.000022).
Papers by and about: Linus Pauling
Summary of Paulings work on vitamin C and colds

Frederick Klenner and Robert Cathcart wrote a series of case reports on using vitamin C in high doses
Irwin Stone summarized the early literature on vitamin C in his book which is available via the net
Papers by Klenner, Cathcart, Stone

Suomenkielisiä C-vitamiinia käsitteleviä kirjoituksia useiden kirjoittajien kirjoittamana
(Finnish papers on vitamin C)

Collection of links to papers describing the Chandra case