Choosing calcium supplements

When looking at calcium supplements, consider these factors:

• Amount of calcium. The amount of elemental calcium in your supplement is important. Elemental calcium is what your body absorbs for bone growth and other health benefits. The Supplement Facts label on calcium packaging tells how much total calcium is in one serving. For example, calcium carbonate is only 40% elemental calcium, so 1,250 milligrams of calcium carbonate contains 500 milligrams of elemental calcium. That is 40% of 1,250. Also, be sure to check the label to see how many tablets equal a serving.
• Side effects. Calcium supplements cause few, if any, side effects. But some people may have gas, constipation and bloating. You may need to try a few different types or brands of calcium supplements to find what is right for you. Ask your healthcare professional if you should take them with or between meals.
• If you take medicine. Calcium supplements may interact with some medicines. These may include antibiotics, lithium, HIV inhibitors and thyroid hormone treatments. Ask your healthcare professional before taking calcium supplements if you take any medicine.
• Quality. There are several calcium supplements available, and the quality varies. It is up to manufacturers to ensure the supplements they produce are safe and their claims are true. Some companies take the voluntary extra step to have their products tested by outside organizations, such as U.S. Pharmacopeia (USP), ConsumerLab.com (CL) or NSF International. Check the supplement packages for USP, CL or NSF seals, which means the supplements meet industry standards for quality, purity and potency.
• Kind of supplement. Calcium supplements come in different forms, including tablets, capsules, chews, liquids and powders. If you have trouble swallowing pills, you may want a chewable or liquid calcium supplement. All varieties of calcium supplements are better absorbed when taken in small doses of 500 mg or less, typically with a meal.