Hi! I hope you could help me. My son is now five years old and already in preschool. He is the only child in his class that couldn't talk properly like kids his age. His teacher can't understand him most of the time. He also is the only kid in class that is very, very energetic and always wander around in classroom. Is there any brand or kind of milk or supplement that contains specific vitamins or nutrients that could help develop my child's speaking ability? By the way, I always talk to him at home and in everywhere we go and he actually is talkative, it's just that someone who's listening can barely understand.