- Calcium carbonate is a naturally occurring compound with the chemical formula CaCO₃, composed of calcium, carbon, and oxygen.
- It is one of the most abundant minerals on Earth and is found in various forms such as limestone, chalk, marble, and calcite. Calcium carbonate is a white, odorless powder or crystalline solid that is insoluble in water but reacts with acids to release carbon dioxide gas. It has widespread applications in industrial, nutritional, and pharmaceutical contexts due to its availability, stability, and calcium content.
- In the nutritional and medical fields, calcium carbonate is primarily used as a calcium supplement. Calcium is essential for numerous physiological processes, including bone formation, muscle contraction, nerve signaling, and blood clotting. Supplementing with calcium carbonate is an effective way to help prevent or treat calcium deficiency, particularly in populations at risk of conditions like osteoporosis, rickets, or hypocalcemia. It is often included in multivitamins or standalone supplements, and is commonly recommended for postmenopausal women, elderly individuals, and people with low dietary calcium intake.
- Calcium carbonate provides a high percentage of elemental calcium (approximately 40%), which means smaller doses are needed to achieve the same calcium content as other forms. However, it is best absorbed when taken with food, as stomach acid helps to dissolve the compound and facilitate absorption in the intestines. Individuals with low stomach acid (a condition more common with age or certain medications) may not absorb calcium carbonate as efficiently and might benefit from alternative calcium salts like calcium citrate.
- In addition to its role as a supplement, calcium carbonate is widely used as an antacid for temporary relief of heartburn, indigestion, and acid reflux. It neutralizes stomach acid quickly, providing fast relief, and is a common active ingredient in over-the-counter products like Tums and Rolaids. While generally safe for short-term use, excessive consumption can lead to side effects such as constipation, gas, bloating, and, in rare cases, hypercalcemia—a condition caused by elevated calcium levels in the blood.
- Beyond human health, calcium carbonate plays a significant role in industrial applications. It is used as a filler and whitening agent in paper, plastics, paints, and coatings, and as a building material in the form of limestone and marble. It also serves as a key component in the production of cement and lime, and is used in environmental applications like flue gas desulfurization and water treatment.
- In agriculture, calcium carbonate is applied to soil as agricultural lime to reduce acidity, improve soil quality, and enhance crop productivity. It is also used in animal feed to supply calcium and improve nutritional balance for livestock.
