"Boniva may cause serious problems in the stomach and the esophagus (the tube that connects your mouth and stomach) such as trouble swallowing, heartburn, and ulcers.Adequate intake of calcium and vitamin D is important.Boniva should be taken at least 1 hour before the first food or drink (other than water) of the day and before taking any oral medication or supplement, including calcium, antacids," . . . .