Quoting HybridMoon:" That's not what I had read when I did my research on it.... After you posted that, I had to go back ... [snip!] ... on. I mean, chances are you won't have a problem with it, but why why why take the risk when you can go to your doctor."
Really though, unless you are reading from reputable medical sources such as the Mayo Clinic, CDC, or other medical bodies then you may or may not be reading factual information. In my nearly 10 years as an RN I've seen overdoses of Vitamin A and other fat soluble vitamins. Nasty stuff. Once you overdose on a fat soluble vitamin it is hell getting it out of the body simply because of the mechanism it is stored using.
Yes you can "overdose" on vitamin C. When you get beyond the point your body can excrete it fast enough then you have Diarrhea, nausea, vomiting, abdominal pain and bloating, headache, insomnia, and potentially kidney stones. None of these things are pleasant but are highly unlikely to kill you.
The biggest risk with Vitamin C is that it improves your absorption of iron. So if you are also taking an iron supplement and large doses of Vitamin C then you could end up absorbing too much iron. That would be potentially fatal.
All in all you may be horribly uncomfortable but you probably aren't going to die from too much Vit C or damage your body permanently.