sunlight exposure

I keep reading that sunlight is good for liver health (and general health for that matter!) I took Pat and Mat to the vet this morning. And I think perhaps it is too soon to conclude much, but Matty had nearly white urates in two of her poops when I got home from work tonight!! I have no idea...

I need advice on full spectrum lighting. Any help would be appreciated! (: Keep in mind that my 3 year old Buster is a chronic egg layer, so this probably makes the situation trickier...maybe. , Her vet advised full spectrum lighting on a timer for 2-4 hours a day. I'm thinking of purchasing...