Water's always a good idea, right? And if a little added flavor can get your kid to drink it, all the better. You've unwittingly entered the danger zone: Flavored waters often harbor hidden ingredients. Some may add vitamins, which many dietitians recommend getting from a balanced diet instead of a bottle. Many of these nutrients (like vitamin C or B) will pass out of the body through the kidneys, but consuming extreme amounts could affect the way your child's body absorbs other nutrients. Plus, flavored water may contain artificial sweeteners, something most experts recommend children consume in limited amounts.