Calcium is important for secreting hormones, cell signaling, muscle and nerve function, as well as for keeping your teeth and bones strong. However, not everyone gets enough calcium from foods. Some people take calcium supplements, but these can have side effects, including constipation, if you don't choose the right supplement or follow the right diet while taking supplements.
Supplements and Constipation
One of the common side effects experienced by people taking calcium supplements is constipation. The two main types of calcium supplements are calcium carbonate and calcium citrate. Calcium carbonate requires the stomach to be acidic for it to be absorbed, so you should take it with food. This is the form of calcium found in antacids that contain calcium. Calcium citrate can be taken with or without food. Calcium citrate malate is a form of calcium used to fortify orange juice. Constipation is more likely with high doses of calcium and with calcium supplements in the form of calcium carbonate, especially if you take calcium carbonate on an empty stomach. Consider taking calcium citrate in doses of 500 milligrams or less at one time to limit the risk of suffering from constipation.
If one type of calcium supplement causes constipation, try another to see if this helps, since not everyone responds the same way to each type of supplement. Whichever type of calcium supplement you take, the best way to limit the risk of constipation while taking calcium supplements is to consume plenty of fiber-rich foods along with six to eight glasses of water each day. Starting with a low dose of calcium and gradually increasing the dose can also help limit constipation.
The recommended dietary allowance for calcium is 1,000 milligrams of calcium for adults between the ages of 19 and 50, and the tolerable upper limit is 2,500 milligrams per day. Keep your combined calcium intake from foods and supplements within this range to avoid the risk of either calcium deficiency or calcium toxicity. High doses of calcium supplements are more likely to lead to constipation, and if you consume excess calcium through supplements you will not absorb it.
The circumstances under which you take calcium affect your risk for becoming constipated as well as the type of calcium supplement you take. Getting as much as possible of your recommended calcium from food will limit the need for taking the dosage of supplements that is likely to lead to constipation. Foods also provide other essential nutrients besides calcium, and tend to provide vitamins and minerals in healthy proportions. Exercising regularly can also help with constipation.
- Office of Dietary Supplements: Calcium
- New York State Department of Health; Commonly Asked Questions About Calcium Supplements; November 2003
- National Institutes of Health; Calcium Supplements: What to Look for; January 2011
- "American Family Physician"; Comparison of Common Calcium Supplements; Barbara Apgar; October 2000
- National Digestive Diseases Information Clearinghouse; Constipation; Michael Camilleri, M.D., et al.; July 2007