Newborns need no extra water. Breast milk or infant formula generally will supply enough fluid.
If your child is sick with diarrhea or vomiting, check with your pediatrician about replacing fluids. Diarrhea and vomiting can lead to dehydration – and it's complications – if fluids aren't replaced. Rather than water or juice, your doctor or pediatric nurse may recommend an oral electrolyte maintenance solution, sold near baby foods in your grocery store, to prevent dehydration. Besides fluid, the solution contains glucose (a form of sugar) and minerals (sodium, chloride and potassium) called electrolytes. Electrolytes help maintain fluid balance in your baby's body cells. These minerals are lost through body fluids.
Consult your doctor or pediatric nurse before feeding an oral electrolyte maintenance solution to children under two years of age (or older children, too). Besides the risk of dehydration, diarrhea and vomiting signal possible illness that may require medical attention! If diarrhea, vomiting or fever persist longer than 24 hours, consult your doctor or pediatric nurse. An electrolyte maintenance solution won't stop diarrhea or vomiting, but it does prevent dehydration.