All carbonated beverages, including diet brands, are acidic in nature. The acids from carbonated beverages enter your bloodstream and are buffered by calcium. However, if the calcium levels in the bloodstream are inadequate, your bones will supply it. Studies have shown that even modest levels of cola consumption are associated with lower bone mineral density scores. And our teeth fare even worse than our bones. The acids in soda damage tooth enamel. As little as a single cup serving of soda a day has been shown to cause significant, irreversible tooth enamel erosion.