Part 1 of your question, no idea - I'd predict the opposite. Part 2, oxidation is simply the process of combining oxygen with other atoms in a substance. O2 easily combines with carbon to form CO and CO2, which is what happens when something like wood burns.
Vitamin C is "the fragile vitamin" because it is sensitive to oxidation. When the juice is exposed to air, the vitamin C it contains degrades. Orange juice stays fresh a day or two if its kept chilled to slow the oxidation rate.