Vitamin supplements are popular items these days. Vitamin C is particularly popular in the winter, when people pop tablets at the first sign of a cold. However, data indicates that vitamin C doesn't actually prevent colds, but long-term use may slightly reduce the severity or duration of a cold when you do catch one. So, should we all start popping vitamin C tablets every day? Probably not. A new study in JAMA Internal Medicine showed that men who took 1,000-mg tablets of vitamin C were twice as likely to develop kidney stones as men who did not take vitamin C...