I have celiac disease. Is it safe to take adora calcium?

Yes, if no gluten. If there is no gluten in the adora ca supplements, then it should be ok to take. Always check labels on all food, vitamins, supplements & meds for gluten. If in doubt, contact the manufacturer. Many supplements will state "gluten-free" only the label, if they are. Gluten is in wheat, barley, rye, triticale, spelt; similar protein (prolamine) is in oats. Wheat flour is sometimes a filler in suppl.
Yes. According to the ingredients listed on adora website adora calcium doesn't contain any ingredients (e.g. Grains) which contain gluten.