Kimmi,
notice, it said "extremely" high levels of calcium. But you'd have to have a blood test to determine if you are in that range. I don't know how much calcium those chews have, isn't the recommended amount like 2 a day? Just guessing here, but I'd think you'd have to eat an awful lot of them on a regular basis to elevate your blood calcium to the harmful levels. In normal circumstances, excess calcium is absorbed by the bones.
As someone pointed out before - dark chocolate is good for you! :D