Although fruit juice consumption offers some benefits according to the American Academy of Pediatrics, it also has potential harmful effects. High sugar content in juice contributes to more calorie consumption and the risk of developing dental caries. Fruit juice offers no nutritional benefits for infants younger than 1 year and no nutritional advantages over whole fruit for infants and children.
Those conclusions are part of a June 2017 policy statement on juice consumption. from the American Academy of Pediatrics.
The AAP also noted that juice should be offered to toddlers in a cup, not a bottle, and infants should not be put to bed with a bottle in their mouth. Allowing children to carry a bottle, easily transportable covered cup, open cup, or box of juice around throughout the day leads to excessive exposure of the teeth to carbohydrates, which promotes the development of dental caries.
You can read their full article here.