If they are weaned mice, then no. No supplements are needed anyway. Calcium, being a mineral, cannot be excreted if there's an excess like water-soluble vitamins and whatnot. So the body just has to deal with the excess. Having an excess can be as detrimental as not getting enough.
http://www.meltdown.com/calcium.htm
This pretty much explains what happens when too much calcium gets in the system.
So that's a no-no on the supplements there buddy. :)