Side effects of calcium supplements

Updated June 13, 2017

Appropriate calcium consumption is necessary to ensure your bones, muscles and blood vessels remain healthy and continue to function normally. If you are an adult and are unable to consume the recommended 1000 to 1200mg of calcium each day, your doctor may recommend treatment with a calcium supplement, according to the US Office of Dietary Supplements. Talk with your doctor about the side effects of calcium supplements before beginning treatment with this dietary mineral.


You may develop constipation as a side effect of taking a calcium supplement, the University of Maryland Medical Center (UMMC) reports. Constipation is characterized by difficult or uncomfortable bowel movements that either yield small, solid stools or no stool at all. If you experience bowel movement problems, you may also develop abdominal cramping or bloating. Seek care from your doctor if you experience recurrent or persistent constipation.

Stomach discomfort

A calcium supplement may irritate your digestive tract, leading to stomach discomfort. You may feel nauseated or begin vomiting, reports. These stomach discomfort side effects may also cause a temporary decrease in your normal appetite. Eating a small snack before taking a calcium supplement may help limit or prevent the development of stomach-related side effects.


Ingesting large amounts of calcium supplements may significantly elevate the levels of calcium in your blood and may cause a condition called hypercalcemia. If you develop hypercalcemia, you may experience calcium overdose side effects, including confusion, increased urination and stomach upset, the UMMC warns. Consult a medical professional as soon as possible if you develop any of these side effects while taking calcium supplements.

Cite this Article A tool to create a citation to reference this article Cite this Article

About the Author

Rae Uddin has worked as a freelance writer and editor since 2004. She specializes in scientific journalism and medical and technical writing. Her work has appeared in various online publications. Uddin earned her Master of Science in integrated biomedical sciences with an emphasis in molecular and cellular biochemistry from the University of Kentucky College of Medicine.