In some children dairy products cause increase of mucus inside of the lungs. Suggest either not giving dairy products before bed and if that does not work, then change to milk substitutions for calcium. The substitutes for dairy products are soymilk, rice milk, almond milk, soy cheese, soy yogurt, soy ice cream, and rice ice cream. Hoped that helped you.
Ok thank you. Just yesterday we went and bought soy milk, kids seem to like. We havent given it to them before bed, so that will be the real test.