i think its pretty normal.. my little one did it as well.. she now only has one bottle a day.. they suggest 2 serves of calcium a day so try get a yoghurt in there or some cheese or something

~ Lala

Completely normal, especially if he is getting plenty of food through the day. Just make sure he is getting plenty of yoghurt and cheese to keep his calcium up.

~ Krystal

Not only is it normal, but it should be encouraged. The natural sugar in milk stays in their little mouths all night and starts to decay their new teeth. To pprevent this give them a little toothbrush to chew on while they watch you brush your teeth (they will be more excited about it if its what mummy does) and make their last drink at night water if possible.
And as above try and get some other calcium rich food in during the day (but avoid more than one serve of cheese cos kids get constipated easily).

~ Alyce