Curiosity.....

[Extensionofgreen]

There have been a few threads regarding UVB, D3, and chameleons recovering natural sunlight and whether they still require vitamin D3 supplementation.
We don't have definitive information regarding how much D3 a chameleon of any given species, age, gender, or health condition may actually need, but we do know that a chameleon exposed to natural sunlight has access to all it could ever need. This brought me to pose the question: Do chameleons have the ability to regulate how much D3 they manufacture, by controlling the pigments in their skin? I'm under the assumption that certain colors would allow for increased absorbtion of sunlight, but curious as to whether that can consciously control, other than by seeking shade, the amount of UVB they manufacture, when exposed to the sun.

 

[Angelwolf]

I would think it's something like a natural process of the body. Similar to the way we produce D3. I think your body just produces what it needs, when it needs it. I don't think the color of the skin would make any difference to UVB absorption, because UVB rays are invisible. I think that a cham who receives natural sunlight is most likely exposed to other healthy behaviors, such as exercise, fresh air, and mental stimulation such as hunting, stalking, etc. I think that's the reason wild animals and animals who make it outside for natural sunlight are generally more healthy. We humans can replicate the UVB they receive, but there's nothing like the real thing! That's just my opinion. I may not be right, but it makes sense to me...

 

[CharlieCharmingo]

I do believe that chameleons can regulate the amount of d3 they receive but I also believe they produce the amount they need. Like @Angelwolf said, if they are exposed to sunlight and healthy activities while in the sun I think naturally the bodies adjusts its self to what it wants and doesn't want needs and doesn't need. However i also think that the amount of d3 they get/make can get "backed up" if they are the sort of chameleon who perhaps doesn't make it outside to the sun as often; because usually when outside they are exploring their plants, on alert, hunting bugs, etc. being active and exerting energy. But if they are more of a inside enclosure animal they don't get to exert the amount of d3 they are getting as much as they would while outside. That's why I think the brands with calcium d3 is usually suggested to be given once or twice a month because it's under the assumption that the chameleon might not go out to sunlight therefore not wanting to overdose the animal on it, if that makes sense. Again no hard proof just my own speculation.

 

[kinyonga]

Dark skin in people affects how much UVB is absorbed...so people with dark skin have to be exposed longer than light skinned people but the color of the skin doesn't stop the production/conversion of the D3....so maybe turning darker or being darker colored affects the chameleons absorption too...
http://www.livestrong.com/article/311881-dark-skin-color-vitamin-d/

 

[Lennoncham]

Here's a link to a case study about d3 absorption in veiled chameleons.

https://www.ncbi.nlm.nih.gov/pmc/articles/PMC4280901/

My mistake that's about calcium absorption but it does talk about uvb exposure as well.

 

[kinyonga]

This article talks about it...but I think the OP is looking for the color chaning affecting it not just the exposure...
https://www.ncbi.nlm.nih.gov/pubmed/19335229

There is some interesting information in this site too concerning transmission of UVB through reptiles' skin including chameleons...
https://www.ncbi.nlm.nih.gov/pubmed/19335229