<<Disclaimer: Verify this information before applying it to your situation.>> Because of the rash of responses I have had since my summary, I felt like I should explain a couple of things. I am not taking the chewable tums nor am I taking the extra strength. The tums I do take have corn starch in them and not just starch. Because I form kidney stones (18 thus far), and had a parathyroid condition, I was sent to an endochronologist to regulate my electrolites. Because of a chemical imbalance, formation of kidney stones and a parathyroid condition, all caused from celiac, I was put on 900 mg of calcium a day. I can't take any other supplement of calcium other than the tums, uricid and k-dur(which is potassium) and a cup of gf yogurt a day because of the kidney stones. I am only allowed 900 mg of calcium a day and it must be from the pills and the yogurt only. I hope this has clarified the situation and not confused it. Simone