I’m getting nowhere with this by asking you what form the vitamin A is in…and believe me, the form of vitamin A is important…so we will try it another way…
There are two forms of vitamin A …prEformed and prOformed.
PrEformed is ready to go…able to be used by the chameleon without it being changed to another form of vitamin A by the chameleon before it’s useful. It’s fat soluble which means the chameleon will store what isn’t used/needed in the chameleon’s body…so it can build up and cause healthy issues. Look for words like retinol, retinal, retinoic acid, etc.
PrOformed vitamin a comes from carotenoids…so from fruits, veggies, greens and is not ready to go in the body…the body has to convert it into a useful form but must be converted into the useful form. The good thing about it is 5at it does not build up in the body because it’s converted as needed….but…the other thing is that it’s thought that chameleons either can not convert it or cannot convert it efficiently… so it’s not of much use to them.
Not only do the chameleons need the right vitamin A, it needs to be in a balance with the vitamin D3 so that it won’t cause health issues.
Now, vitamin D3 comes to the chameleon in two ways too…preformed…ready to go…builds up in the system, if given too much. This comes in the powders we use to dust the insects with. D3 from supplements is also fat soluble and can be stored in the body leading to health issues.
Then, there is the form that the body converts as needed and doesn’t usually cause any problems because it comes from the sun or the UVB bulbs we use on the cage, and as long as the chameleon can move in and out of the shade/light as desired it shouldn’t overdose.
Vitamin D plays an important part in bone health…and vitamin A is important in many systems too…so they all need to be in a balance.
Here are some articles that you might like to read…
http://www.chameleonnews.com/07FebWheelock.html
http://www.chameleonnews.com/03JanDonoghue.html