Had to laugh when I read that. There is a masive smear campaign against vitamins, particularly vitamin C by the drugs companies who control all aspects of Western medicine and see people getting healthy with nutrients they can't licence as a threat to their business. You may think I'm paranoid but the evidence is clear. The kind of article you pointed to is one of many they put out to blind people to the truth which is that nobody ever died or was made seriously ill by vitamin C whereas 100,000 people die every year in America alone (around 10,000 in the UK) from drugs prescribed to them by their doctors. These figures may sound unbelievable but are true and I kow what I'd rather take - my current 4g average of vitamins C which is non toxic or some drug that may have massive and possibly fatal effects (they call them side effects which is marketing speak for effects). Like I say I am extremely fit and healthy for my age and will continue to take my vitamin C until the drugs companies finally manage to take it off the shelves.
I can imagine it took more searching to find something bad about vitamin C than something good as its generally recognised to be not only good for health but more essential than we ever thought. See www.vitamincfoundation.org/
(among many many many others) who are a non-profit organisation dedicated to helping people through promoting this essential nutrient.
btw too much doesn't throw the balance of the body out like the fat soluble vitamins, being a water soluble vitamin if you take more than you need you just excrete it.