In the world of vitamin C, it is hard to find anyone who will say anything bad about this vitamin.
I've heard one person say that it can cause kidney stones.
However I doubt that because with as many people taking large doses of vitamin C, you would think that a connection between vitamin C and kidney stones would have been established by now if it were the case.
I have however found a Doctor who rather than believe in antioxidants such as vitamin C, believes in pro-oxidants, or at least the free radicals that occur naturally in the body.
He stated that supplementary vitamin C is not needed unless you have a known deficiency.
Vitamin A and E (an antioxidant) and beta carotene need to be taken with care if it all.
He is Randolph M. Howes (M.D., Ph. D), a plastic surgeon with a Ph.D. in biochemistry.
His position, which he states in his book, in youtube videos, and on his website, he suggests that oxygenization is the primary process for fighting bacteria, fungi, and protozoa such as malaria, as well as for destroying cancer cells.
This being the case, he states that you have no business interfering with the oxygenization process with antioxidants, of which vitamin C is one.
He claims he has many research studies to demonstrate his point, which he has summarized in his book.
It also appears you can download a lot of information for free on its web site.
(www.iwillfindthecure.org)
I do not really know what to make of this, but it does seem to demonstrate the difficulty we have with establishing the optimal levels of vitamins to take for best health.