@Extensionofgreen said..." there are many suggested sources stating that chameleons lack the ability to convert preformed A into useable Vitamin A"...you said convert prEformed... Do you mean prOformed?
Do you know of any scientific articles/studies that you could link me to that say they can't convert prOformed to vitamin A? I'd like to read them. I'd also like someone to explain to me how my vieled females, for example, have never shown any signs that I could see of hypovitaminosis A in the 6 or 7 years that they live, not have their offspring and yet I give no prEformed vitamin A to the insects or chameleons in any form. I do realize that the insects might have some due to what they were fed...but then so would everybody else's. It's always been a mystery to me.
I have always wondered if chameleons that seem to lack vitamin A do so because they are fed too much D3 from supplements too. I'm wondering if thats not part of what Dr. Lopez felt/feels too. Any inside into any of this? For many (over 25years) I've dusted the wayni always describe to people...every day with phos. free calcium, twice a month with phosphorous-free calcium/D3 and twice with beta carotene CO raining vitamin powder lightly and my chameleons seem to do well...no eye issues, no shedding difficulties, no MBD etc. I don't think any of us measure exact amounts and with all the different supplements out there I can't see how we can ever say this is the way it has to be. Maybe someday we will have the answers. In the meantime we just have to do the best we can.
I did mean to say that chameleons are unlikely to have the ability to convert precursors or PROformed A into useable PREformed A.
Please know I am not saying this to poke fun or be snarky, but a while back, YOU posted links from sources that echoed what I’m saying about chamelons needing preformed A. I remember reading them and thinking that it was an interesting share, since I know you often recommend against supplementation with PREformed A.
I don’t have a cache of articles I can link or share, but they are out there, I assure you. I don’t think Vitamin A is something that the reptile medical community has an adequate understanding of and that accounts for a lack of available articles. I don’t recall what the Arcadia book on the subject had to say, but I do have it at home and I believe it also mentions the lack of ability for insectivores to convert PROformed A to useable forms.
Regarding explaining the health of your animals in the absence of Preformed A supplementation, I don’t have a perfect answer. I could ask you to explain what my animals suffered without it, then improved and had a complete cessation of occurrences once it was implemented. I would expect your answer to be similar to mine, in that there isn’t a perfect answer. The variables are many and poorly understood by the community, currently.
What are you using for gutload that might be able
carry PREformed A to your chameleons? Are feeders able to convert some ingredients for supplements into PREformed A? I know that feeding my feeders sweet potato and powdered milk ( as part of the total gutload mixture ) wasn’t enough for raising my melleri. Pet store crickets fed on chicken feed or other pelleted foods will get Vitamin A that way and could be a source of sufficient A. My chameleons were fed primarily on roaches, when they suffered from A deficiency, so that offers a theory that answers your scenario and my own. Not all pet stores will feed Vitamin A sources, so there’s another variable!
What I can tell you is that Vitamin A is found in nature, in the eyes of some Arthropoda, more so than most insects, and in the livers of vertebrate prey. Our chameleons get few to none of these prey items I’m captivity.
I don’t disagree that there is danger in overdoing supplements and animals that have had episodes of dehydration and edema are especially sensistive to overdosing vitamins.
