No discussion on UVB needed, it had been beaten to death topic already.
Once again - different species have different requirements. What's good and must for one, might be really bad for the other.
Albino morphs of any species can not have any UVB at all, for some species exposure might be harmful, for the others lack of UVB will be harmful and even deadly.
Just one of the useful readings available to general public with summary of data and scientific papers available
http://amphibiaweb.org/declines/UV-B.html