Calcium Carbonate
Calcium Carbonate
Snapshot
Calcium carbonate is a widely used calcium supplement that supports bone health, nerve transmission, muscle function, and overall mineral balance.
What is Calcium Carbonate?
Calcium carbonate is a naturally occurring compound composed of calcium, carbon, and oxygen. It’s commonly used in antacids and dietary supplements to increase calcium intake, prevent bone loss, and maintain proper muscular and cardiovascular function.
Where It Comes From
This compound is derived from natural sources such as limestone, chalk, and marble, or from marine shells like oyster and snail shells. It is one of the most common and affordable forms of calcium used in nutritional products.
Key Nutrients & Compounds
Calcium carbonate provides elemental calcium, which is the actual amount of absorbable calcium in the supplement. It contains about 40% elemental calcium by weight, making it one of the most concentrated forms available. It does not naturally contain additional co-factors like magnesium or vitamin D.
Health Benefits
Calcium carbonate promotes strong bones and teeth, helps prevent osteoporosis, and supports heart and muscle function. It plays a key role in blood clotting, nerve conduction, and maintaining normal acid–base balance. It is also used to relieve symptoms of heartburn and acid indigestion when taken in antacid form.
Recommended Dosage
A typical dose ranges from 500 mg to 1,000 mg per day, often divided into two smaller doses. Since it requires stomach acid for absorption, it should be taken with food. Exceeding 2,500 mg per day is not recommended due to the risk of hypercalcemia and kidney stones.
How to Use It
Available in tablets, chewables, capsules, and powder, calcium carbonate should be consumed with meals to ensure proper absorption. Pairing it with vitamin D3 is highly recommended to enhance calcium uptake in the intestines.
Who Should Use It?
Beneficial for individuals with low calcium intake, those at risk of osteoporosis, and postmenopausal women. It’s also suitable for people needing a cost-effective calcium supplement or relief from acid reflux symptoms.
Possible Interactions or Cautions
May interact with medications like tetracycline antibiotics, thyroid hormones, and iron supplements. High doses can lead to constipation, bloating, or interfere with the absorption of other minerals. People with kidney issues or those prone to kidney stones should use caution and consult a healthcare provider.
Final Thoughts
Calcium carbonate is an effective and economical way to support calcium levels, bone strength, and digestive health. When taken correctly with food and co-nutrients like vitamin D, it remains a staple in mineral supplementation.
Scientific Studies
Straub, D. A. (2007). Calcium supplementation in clinical practice: a review of forms, doses, and indications. Nutrition in Clinical Practice, 22(3), 286–296. https://doi.org/10.1177/0115426507022003286
Heaney, R. P., et al. (2001). Calcium absorption varies within the reference range for serum 25-hydroxyvitamin D. Journal of the American College of Nutrition, 20(3), 307–311. https://doi.org/10.1080/07315724.2001.10719043
Martini, L. A., & Wood, R. J. (2002). Relative bioavailability of calcium-rich dietary sources in the elderly. The American Journal of Clinical Nutrition, 75(6), 1357–1362. https://doi.org/10.1093/ajcn/75.6.1357