I believe Repashy has calcium with vitamin D3 in it. Peek at the ingredients.

Calcium without vitamin D3 is not helpful. Vitamin D3 helps with the absorption of calcium. Because we do not provide enough vitamin D via sunlight, we need to replace what they are not getting naturally. Calcium deficiencies can lead to tetany and loss of motor functions and if severe enough can lead to paralysis, seizures, and Metabolic Bone Disease. For the best absorption, I always recommend it with vitamin D3.

This actually applies to humans as well.

When using a vitamin D3/calcium supplement, dust lightly every other day.

Signs of low blood calcium levels are numbness and tingling (which we can't really assess in amphibians), twitching, stiff like motions of joints or lack of ability to control movements, tremors, seizures, paralysis. You will see that the bones become soft and weak. It will also affect their bone marrow, which therefore can lead to anemia.