Calcium Antacid 500mg by Major Pharmaceuticals are comparable to Tums , and provide relief to common stomach issues. Made with 500 mg of calcium carbonate, these tablets are chewable and come in Mixed fruit flavors. For instant relief of your upset stomach due to heartburn, acid indigestion and sour stomach try Major Assorted Flavor 500mg Calcium Antacid tablets. Each tablet is chewable for easy swallowing and they come in great tasting assorted fruit flavors.