Almost all animals need UVB to create D3 to process calcium. The question is how much. Humans only need about ten minutes' exposure per day on the hands and face. Fast growing lizards need a lot more. Nocturnal animals much, much less (and there is ambient UV even at night.)
Calcium deficiencies are common in turtles, and it's suggested to put them out for some UV on a regular basis (careful not to cook them) or to provide a UVB light.
Here's a caresheet from Melissa Kaplan's site for RES:
http://www.anapsid.org/reslider.html
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