Calcium carbonate comes from limestone. You may know it in over-the-counter medication to relieve heartburn or for indigestion (antacid) or as a calcium supplement in tablets or in various beverages like plant-based beverages that have no naturally occurring calcium.
As a food ingredient, calcium carbonate is used as an anti-caking (prevents lumps) ingredient for flours, baked items and frozen desserts.
Source: https://pubchem.ncbi.nlm.nih.gov/compound/Calcium-carbonate#section=Pharmacology
Leah McGrath, RDN, LDN
Ingles Markets Corporate Dietitian
facebook.com/LeahMcgrathDietitian
800-334-4936