You mean processes we don't know about? Probably they're out there. In general since a few animals including man lack the enzymes needed to make vitamin C themselves one might imagine that all the rest are indeed benefitting in various ways from that inbuilt metabolic advantage.
"current evidence favors the hypothesis that the multiple gains and losses in the ability to synthesize vitamin C are random, as would be expected for a neutral trait." - http://www.ncbi.nlm.nih.gov/pmc/articles/PMC3145266/
I'm a 6'5" 300 lbs male. I was taking upwards of 7g a day of vitamin c. Past that, I would get heavy flatulence, explosive diarrhea, and general gastronomic distress. I felt no change on my inside for doing excessive C, nor did I have any size effects other than the ones I noted for going past that.
One case, when I got sick, I was taking C. I wanted the illness to quit quickly, because I didn't want to be sick. So I took 8g C, 2 tablets of echinacea, and a NSAID. What happens was worse than any cold ever thought about being.
I killed off all my flora and fauna in my intestines. With this brought massive burning diarrhea (from the unneutralized stomach acid). I had this situation for 5 days straight. I was on the toilet at least 20x a day, day and night. Finally, day 6 had the formation of stool, which I cheered at. Day 7 and I was somewhat back to normal.
