Toe-kick vent

Is your bathroom over a crawlspace or basement? It would have been better to do the ducts before yo completed the work. Are you using the vent just for heating or do you air condition as well. What climate do you have?

Check this out. If you are using ac in a humid climate, you could grow mold or rot in your crawlspace or basement under your vanity toespace grille.

Crawlspace problems

Stretch

sorry - I didn't mean to reply just to Stretch, so here I go again:

I've already installed the duct - actually moved it (it was a vertical vent about 6 foot tall into the wall before I knocked it out to build the bathroom. I believe it's just used for heating, but it had a return and a send before (top and bottom of the old vertical vent). I also have cold air vents in the bedroom itself.

I live in Nebraska - so it gets all of the seasons - hot, humid summers to cold winters.