When I was still working all the time, I had a routine in the morning, and took a bunch of OTC vitamins and stuff, including vitamin C. I know there is no medical evidence that it prevents colds, or whatever, but it seemed like there were lots of opportunities to get colds that just didn't happen. Since retiring, the routine has gone away, I don't take vitamin C regularly. I have a cold right now that is wearing me out. I don't know, maybe it's bogus, but I still feel like vitamin C works to help fend off colds.