This sheet is about exposure to calcium carbonate in pregnancy and while breastfeeding. This information is based on published research. It should not take the place of medical care and advice from your healthcare provider.  What is calcium carbonate?  Calcium carbonate is a dietary supplement that has been used as an antacid to help symptoms of heartburn, acid indigestion, and upset stomach. Some examples of over-the-counter antacids with calcium carbonate are Tums®, … Continue reading Calcium Carbonate