Ok, I'm doing tons of research on calcium supplements trying to settle one one to use in the future (Current bottle is running low, and I hope to be expanding my collection in the future as well) At any rate - I have heard numerous times that Calci-Sand is bad - it boils down to it being made of Calcium Carbonate. If I remember correctly, anyways. Many of the calcium supplements I am finding, once I read the fine print, are 100% calcium carbonate. Some are derived from oyster shells. Don't know if that figures into it. Umm? Is this somehow different than calci-sand? Is there something I'm missing? If Calcium carbonate is bad as Calci-Sand, wouldn't it be bad as a supplement too?