In the hysteria and exaggeration that surround health issues, personal experience and judgement seem to count for nothing. I try to eat plenty of fruit and veg, not because I might avoid colon cancer, but because I feel heathier and fitter for it. All the research indicating that it might help you live longer is reassuring but not my primary reason for doing it.
Moderation is the key. This also applies to vitamin supplements. Even if you have a balanced diet, if you have a cold, say, low doses of vitamin C for a period might be a good idea. Mr Laurance quotes a report suggesting that "mega" doses might be harmful. Surprise, surprise. Water is essential for life, but drink enough of it and it will kill you.
RICHARD G REDDING