Calcium Carbonate
This is what the ingredient is.
Calcium carbonate is a mineral compound naturally found in limestone, chalk, and shells. Most common calcium supplement and antacid.
Here is why it shows up on the label.
Calcium fortification in foods and beverages, antacid, and anticaking agent. Used in orange juice, plant-based milks, and supplements. Also used as white colorant.
Here is what food agencies say.
The FDA lists it as Generally Recognized as Safe. RDA for calcium: 1000-1300 mg/day depending on age. Upper limit: 2500 mg/day. It is approved in the US, Europe (as E170), and Canada.
Here is what research has found.
Essential mineral for bone health. Carbonate form contains 40% elemental calcium (highest of calcium salts). Requires stomach acid for absorption. Studies in Osteoporosis International examine bone health effects.
Here are a few things worth knowing.
Generally safe at recommended intakes. Very high supplemental intake (>2000 mg/day) may increase kidney stone risk and cardiovascular disease risk according to some studies. Can cause constipation, gas, bloating. May interfere with absorption of certain medications. Food fortification levels are safe.
Sources
- FDA Regulations
- NIH Calcium Fact Sheet
- JAMA Internal Medicine 2013 - CVD risk study
How to read this page
We publish plain facts about this ingredient so a label is easier to read. This is not medical advice, and it is not a recommendation to buy, avoid, or use anything. For a personal health question, talk with a clinician who knows your history.