Reptile & Amphibian Forums

Is it possible that too much Vitamin A (rather, beta carotene) and/or Vitamin D can cause MBD-like symptoms or Soft Tissue Mineralization?
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SandraChameleon@gmail.com
BC Canada

Yes.
From a well known article written by a bunch of experts.

"Hepatocellular lipidosis, indicating a possible toxicosis, occurred with all diets and light treatments. Higher vitamin A resulted in mild soft-tissue mineralization, and high vitamin D shortened the life span of females"

Does the article refer to preformed or beta carotene?

Both.
Why? you suspect something?

It has been my understanding that when vitamin A is taken as beta carotene it doesn't build up in the system. What is needed is used and the rest just passes out of the system. Extra preformed gets stored. If the article talks about beta carotene causing problems...then I would like to read about it.

Thanks for the link MetaC!

Please name your sources?

I'd like to continue my research on this.

I am in a situation where a person has said a healthy chameleon quickly came down with symptoms presenting like MBD and/or soft tissue mineralization. Since I have its siblings in my care, I am concerned to determin if anything in my husbandry is lacking. So far the siblings of the cham in question have checked out fine save one, which does show up as have very very minor soft tissue mineralization. I find it odd that one would show this way when all the others are in perfect health.

I am hopeful that its acutally a non-issue, given that I have long-lived chams raised under the same conditions.

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SandraChameleon@gmail.com
BC Canada

Unfortunately, I have read books from well known authors that both agree with and contradict your quote. you dont say where you quote from.

I am more interested in the opinions of people who have chameleons themselves, than quotes from unnames sources.
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SandraChameleon@gmail.com
BC Canada

oh ok. opinions?
Make the quote i wrote my opinion. (and i've been breeding many locales of panthers for 6 years now -but i don't know what my experience has to do with it since I don't have the equipment to measure nutritional deficiencies and/or excess).

oh. and chameleons cant use beta-carotene as a source of vitamin A like omnivores or herbivores would do, at least, not in high rates. so if you only gave beta-carotene to your chameleons without preformed vitamin A, they most likely have vitamin A deficiencies. At worst, it would cause MBD or premature death. but then again, this is only my opinion.

Thanks for this. I have been avoiding preformed A and ensuring lots of Beta Car, as this was what I'd read was the "right" thing to do. My cricket and roach gut load tends to frequently include carrot, sweet potatoes, yams, squash, dandelion leaves, which I believe are all high in Beta Car.

What do you recommend as a good source of preformed A, and what amounts?

Anyone else have an opinion on Beta Carotene vs preformed Vitamin A?

What are symptoms of lack of A?

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SandraChameleon@gmail.com
BC Canada

I use Acetate and the doses varies on the weight of your chameleons.

have a look at this:
http://www.peteducation.com/article.cfm?cls=17&cat=1796&articleid=3027

I have been keeping/breeding/raising chameleons for over 15 years...including pardalis. Its been a long time since I have had one with MBD that I hatched and raised.

I'm not a vet and the following is what I have learned from experience, learned from others or read. Included in the following is also what I do in the way of supplementing, etc.

The four main players in bone health are calcium, phosphorous, vitamin A and vitamin D3. They need to be in balance. Because insects usually have a poor ratio of calcium to phosphorous, I dust the insects with a phosphorous-free calcium powder at most feedings. This is intended to even out the balance of phos. to calcium. Vitamin D3 and vitamin A are fat soluble and thus they can build up in the system. A chameleon exposed to UVB (from sunlight or UVB tube lights) will produce its own vitamin D3....and it shouldn't get an overdose from producing it this way. The light must not pass through glass or plastic or the UVB will do the chameleon no good. Because my chameleons get no direct sunlight (only UVB from tube lights), I dust with a calcium/D3 powder a couple of times a month lightly. Vitamin D3 from supplements can build up in the system...so you need to be careful not to overdo it. Beta carotene (from veggies, greens, etc.) can not build up in the system....and from what I've read, is converted slowly into vitamin A. Beta carotene that is not used is supposed to just go out of the system. Vitamin A (preformed/retinol/animal sourced) can build up in the system. However there is a controversy as to whether chameleons can convert beta carotene or not...so some people say that vitamin A from a preformed source is needed by chameleons too. In addition to all of this...vitamin A is antagonistic to vitamin D3 and too much vitamin A can interfere with vitamin D3 and lead to MBD. BTW...insects don't have much vitamin A in them. In addition to dusting with the (phos.-free) calcium and the calcium/3 as I have already described, I dust lightly twice a month with a vitamin powder that contains beta carotene sources of vitamin A.

As if this weren't enough...people don't look at what they gutload the insects with....if you use dog food, chicken chow, etc. they may/will contain vitamin A and D3....which you need to take into consideration in the balance for bone health. (I gutload my crickets with an assortment of greens and veggies.)

Then, there are people who feed their chameleons pinkies, etc. which also alter the levels of D3, A, phos. and calcium that are being brought into the chameleon's diet.

Concerning the development of MBD...it is not something that just creeps up overnight....there will be subtle signs at first that might not be noticed (inablility to lift the body off the branch, flexible jaw or casque, etc.) until the bones become so weak that a sudden strain, bump, or fall causes a fracture or other obvious sign.

Rapid growth plays a part in all of this too...if the chameleon is grown rapidly, IMHO, the bones have a hard time to keep up unless the nutrients needed are supplied in the right amounts too.

Appropriate basking temperatures also play a part in the health of a chameleon....if the chameleon can't digest its food at the right rate because it is too cool, then the absorption of nutrients is going to be affected too....IMHO.

Now...here are some sites that talk about some of what I have said...
http://www.seavs.com/case_studies/lizards/chameleons.asp
"Chameleons kept indoors have been found to have problems with vitamin D3 and vitamin A in particular. A relationship exists between these two vitamins and their amount of supplementation in chameleons. The exact requirements for vitamin A and D3 are currently unknown. Ongoing research may help us to better understand their relationship and how we should properly supplement. Some things are worth noting:

* The exact requirements for vitamin A and D are no the same for all chameleon species and are higher for growing juveniles and reproductively active females.
* Excessive vitamin A supplementation may result in interference of vitamin D3 metabolism, leading to MBD.
* Excessive vitamin A supplementation may result in organ toxicity (kidney and liver) some times causing gular edema and reproductive problems such as sterility.
* Inadequate amounts of vitamin A may cause eye problems, neurological dysfunction, spinal kinking, dysecdysis and the formation of hemipenal plugs.
* Excessive vitamin D3 supplementation can result in organ toxicity (gular edema)metastatic calcification, gout, and pseudo-gout (calcium-like deposit).
* Inadequate amounts of vitamin D3 (either in the diet or by conversion from exposure to ultraviolet light) can lead to MBD.
* Treatment for hypovitaminosis involves immediate supplementation of the low level of vitamin in question either by injection or orally, supportive care with fluids and supplemental heat, if necessary, providing natural sunlight (best) or ultraviolet irradiation and ul timately adjusting the diet and/or UV exposure to attempt to provide the necessary vitamin levels.
* Treatment for hypervitaminosis is more difficult as organ toxicity and damage has usually occurred by the time clinical signs have been noted (e.g. gular edema with kidney damage). Aggressive fluid therapy (see therapy for infectious diseases), exposure to natural sunlight, providing a lower protein diet and using phosphate binders such as Amphogel may be helpful. If hypervitaminosis D and metastatic calcification is suspected."

I have never found anything that refutes what this article said concerning carotenoid precursors...so I can only assume that it is right and that beta carotene can be converted by chameleons...
http://www3.interscience.wiley.com/cgi-bin/abstract/95016303/ABSTRACT?CRETRY=1&SRETRY=0
"Measurable concentrations of retinol at all stages of egg development in the chameleons suggests effective conversion from carotenoid precursors".

http://adcham.com/html/veterinary/mbd-fractures-kramer.html
http://www.peteducation.com/article.cfm?cls=17&cat=1796&articleid=3027

There were several good articles on Chameleon Journals concerning MBD, vitamins A and D3....but unfortunately its down now...
http://www.chameleonjournals.com/faq/

"Reptile Medicine and Surgery", 2nd Edition, edited by Douglas R. Mader, MS, DVM, DABVP. You'll be more interested in chapter 18 on vit A by Dre Susan Donoghue. 72 contributing authors, mostly Vets

Mostly, it talks about how lizards like chameleons can't process beta-carotene like herbivores do thus leading to the problem you mentionned.

"Vitamin A in chameleons has a long, twisted, almost-sordid history. About, hmmm... maybe about 8 or 10 years ago or so, a fellow named John Annis was editor of the Chameleon information Network, and found what he thought was a link between excess vitamin A and edema in chameleons. He wrote up a detailed report and published it in the CiN. The chameleon-owing public grew quite alarmed about vitamin A, at least one company marketing a supplement switched their vitamin A to A's precursor beta-carotene, and the effects still linger today. Unfortunately, Annis' paper wasn't peer reviewed, wasn't based on controlled trials, and there was likely some erroneous observations (eg several other nutrients were also involved, not just vitamin A, which he didn't recognize or report). You can read Dr Stahl's publications on the large number of cases of vitamin A deficiency in chameleons in the mid-90s because people stopped dusting with vitamin A (Dr Stahl has a nice paper on this in the International Herpetological Society, Advances in Herpetoculture 1996).

Vitamin A definitely can be toxic when given in excess doses. Invertebrates have low levels of vitamin A, and it looks as if dietary requirements for chameleons are lower than req for mammals, birds, and carnivorous reptiles --- but there are enough reports in the veterinary literature of vitamin A deficiency in chameleons when owners quit using vitamin A. We don't yet have evidence that chameleons can convert carotene to vitamin A, and chances are (from data available), they cannot convert at a high rate.

Current thinking is to dust with LOW vitamin A and low-to-medium beta-carotene. Give crickets low-to-medium vitamin A and high beta- carotene."

Cheers,
Sue
Susan Donoghue, VMD, DACVN
Owner, HerpNutrition

The good news is that all of my Chams are fine. Even the one that seemed to possibly have some minor soft tissue mineralization has subsequently been found 100% fine. I've decided to stick with my old system and gut loads, with one very minor exception. I now give my roaches some kibbles that have preformed vitamin A about once a month. These roaches may thus be transferring some of this A to the chams now. But otherwise I rely on the beta c to do the trick.
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SandraChameleon@gmail.com
BC Canada