Your frog really doesn't need a UVB light and as for a calcium bath, just add a pinch of calcium supplement to the water dish. Calcium is processed through digestion and not really absorption but can't hurt if you need to get something into the frog quickly.

You should dust the frogs crickets with a calcium supplement two to three times a week and once a week with a citimum supplement.
If your frog had convulsions or found in almost a paralyzed position, then you will need to do catch up so dust with calcium daily for about two weeks.

Hope this helps