There is no food in it's natural state that has calcium carbonate. However, calcium as a supplement is usually calcium carbonate because it is extremely cheap!
I believe calcium carbonate is added to a lot of prepacked foods on the market...bars, drinks/shakes, etc.....check labels!
It's really hard to get all the calcium, vitamins, and minerals you need from food since many of the foods are from hybrid seeds. Hybrids just don't gather all the nutrition from the earth that open pollinated plants do. It's all about the money any more. Genetically Modified foods and Hybrids. But I guess that's a whole other subject.