Hi Lisa! I'm from Canada, and we have Tums here, too: they are an antacid made primarily from calcium carbonate. CAH kids are benefitted, of course, by taking a calcium supplement, because the steriods we give them tends to leach calcium from their bones, possiblly resulting in problems later on. Hope this helps! (How are the Olympics going?! I wouldn't mind speaking to you someday just to chat! - my husband has an opportunity for a job exchange to Australia in the next year or two, and we've never been there. If you're interested and have time for a little chit-chit, please e-mail me at: kruesel@escape.ca Thanks & God bless!)