Look for 100 percent fruit juices. Nutrient-rich picks: Purple grape juice, cranberry juice (both are high in antioxidants), and OJ, which is loaded with vitamin C, potassium, folate, and sometimes added calcium.
Limit yourself (and older kids) to 6 ounces a day. Kids 6 months to 12 years old should have no more than 4 to 6 ounces a day. (Skip it for babies younger than 6 months.)
If your child wants more, dilute it with water to make it go further.