they are off on Sunday... Question for all about the calcium supplements

...What exactly makes them bad? Seems that the formation of those skeletons (albeit tiny skeletons) within her, if she doesn't supply enough calcium to them, you would think that it would be detrimental for them or they might draw it from her frame. Is there a possibly of stones forming?
I checked her food (Science Diet Puppy) and they don't mention calcium in the ingredients. So I'll need to get it to her some how.