My daughter frequently falls a sleep multiple times a day in class at school. She has seen her pediatrician and the suggested melatonin which takes nightly (if she doesn't she will be up all might) what could be the cause of her being so tired all the time could she be anemic or diabetic or have a vitamin deficiency or something? She has a neurology appointment in a few months but I'm just trying to figure if it could be something else. Has anyone experienced this with a child?