Why not take another type of calcium supplement and then you won't have to worry about it? Regardless of which you take, just make sure you don't take it within four hours of taking your thyroid medication. Same with iron.

If you are really set on taking the coral calcium for some reason, you should talk to your doctor about this. The amounts in the supplements may not be high enough to worry about or they may be. This is probably a question they can just answer over the phone. Remember to always tell your doctor about all other medications and supplements you are taking when you see him, even if they are over-the-counter.