Calcium carbonate is widely used medicinally as an inexpensive dietary calcium supplement or antacid. It is also used in the production of toothpaste because it clashes with acids.
It can be classified according to powder size into: heavy calcium carbonate (30 ~ 50μ m), light acid calcium (5μ m) and colloidal calcium carbonate (0.03 ~ 0.05μ m), three kinds. Colloidal calcium carbonate is most easily absorbed by the body.