Gluten Free Diet And Calcium Sup

I was curious…i was at a local Gluten Free meeting last night (about 12 moms) and not one used a calcium sup. We use the powder from kirkmans and one mom said that their DAN doc said not to use that..I can understand that some kids might have too much calcium in system but it seems odd that none use it. What about you guys?Who uses a calcium sup and if so which one- or why not XYZ? Feel free give me your comments.