Q. Can I use 12-3 NM cable to wire the bathroom GFCIs and laundry circuit in a dwelling?
A. Sure, if you use a GFCI receptacle for the first outlet for the bathroom receptacle circuit, and all down-stream receptacles are supplied through the GFCI receptacle.
Be aware that the continuity of the grounded (neutral) conductor of a multiwire branch circuit (before the GFCI receptacle) must not be interrupted by the removal of a wiring device. Therefore, the grounded (neutral) conductors before the GFCI receptacle must be spliced together, and a pigtail must be provided for the wiring device [300.13(B)].