Quote Originally Posted by jylesa View Post
I found one (and only one I guess) study about this, probably the one that O'Mathghamhna found:

The effects of UV light on calcium metabolism in ball pythongs (Python regius)
Vet Rec. October 2013;173(14):345.

J Hedley1; K Eatwell

Article Abstract

Despite the popularity of keeping snakes in captivity, there has been limited investigation into the effects of UV radiation on vitamin D levels in snakes. The aim of this study was to investigate the effects of UV-b radiation on plasma 25-hydroxyvitamin D3 levels and ionised calcium concentrations in ball pythons (Python regius). Blood samples were taken from 14 ball pythons, which had never been exposed to UV-b light, to obtain baseline 25-hydroxyvitamin D3 levels and ionised calcium concentrations. Blood samples were then taken again from the same snakes 70 days later after one group (Group 1, n=6 females) were exposed to UV-b radiation daily, and the other group (Group 2, n=5 males and 3 females) were exposed to no UV-b radiation. Mean±sd 25-hydroxyvitamin D3 levels on day 0 in Group 1 were 197±35 nmol/l, and on day 70 were 203.5±13.8 nmol/l. Mean±sd 25-hydroxyvitamin D3 levels in Group 2 on day 0 were 77.7±41.5 nmol/l, and on day 70 were 83.0±41.9 nmol/l. Mean±sd ionised calcium levels at day 0 were 1.84±0.05 mmol/l for Group 1, and on day 70 were 1.78±0.07 mmol/l. Mean±sd ionised calcium levels at day 0 were 1.79±0.07 mmol/l for Group 2, and on day 70 were 1.81±0.05 mmol/l. No association was demonstrated between exposure to UV-b radiation and plasma 25-hydroxyvitamin D3 and ionised calcium concentrations. These results may provide baseline parameters for future studies in this and other snake species to determine ability to utilise UV-b light for vitamin D production.

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I poked through the full article and it seems like a generally underresearched topic, and I couldn't find any other articles talking about whether or not it helps them. The study made use of only a few animals (14 total for both the control and experimental groups) but it seems like it does no real harm to them in terms of Vitamin D3 and calcium absorptions. For what it's worth, the bulb they used is ReptiSun 5.0 UV-b Fluorescent bulb by ZooMed. Anecdotally, I guess they seem to do well with the light, so your vet perhaps recommends it for that reason.
Thank you!! This is the article. I just wanted to understand it a little better than just the bolded part... I may try using the bulb I have on my rescue going through lots of med treatments. I'll put it on a timer and see if that maybe helps at all, although I'm not sure how I could even measure that. ?