Breast milk and formula are both about 90 percent water. Still, rumors persist that you should give “100 percent water” between feedings. The problem with 100 percent water is that it lacks the all-important 10 percent: the nutrients in milk. If you’re breast feeding, you should drink lots of water yourself to help replenish your fluids, but Lucy gets enough water from milk or formula. This is true in hot weather as well. Extra water is unnecessary until six to eight months of age. Unlike adults, who can forget to drink fluid, a baby’s diet is all liquid and therefore poses no risk of dehydration.
There are other myths about water. Some suggest you give Lucy sugar water to stimulate her intestinal movement and induce stool production despite the fact that it’s very normal for a baby to go many days without pooping [See: Stools]. You don’t have to resort to hydration for this purpose, and that method doesn’t really work anyway. Others advise giving her a bottle of water as a pacifier. A regular pacifier will do just as well.
If, after all these arguments, you still wish to give your young baby water, go right ahead; in small quantities, it certainly won’t do any harm.
In Infants and Toddlers
While continuing to provide formula and/or breast milk, begin giving Lucy water around eight months, the age at which she’s eating a significant amount of solid foods. Water is always preferable to juice, partly because it helps prevent the development of a sweet tooth and doesn’t reduce appetite. Her daily water requirement is whatever quantity she takes, as long as you offer it at meals and snacks and in between if the weather is warm.