Carrots and Vit A?
- Thread starter Syn
- Start date
Ryan Jarosek
New Member
Ryan Jarosek
New Member
I know humans convert what they need. I am not sure for chameleons.
I not really clear if chameleons affectively convert beta carotene into Vit A at all or not efficiently. Maybe someone will provide some input.
If you search the forum you should be able to find some better explanations than mine.
Syn
Avid Member
Quoted from another thread:
So if I feed my dubia carrots, there is a chance my cham could OD on vit A?
https://www.chameleonforums.com/vitamin-scares-me-12395-post117713/#post117713
Found an answer, thank you search button *smacks forehead*.
So if I feed my dubia carrots, there is a chance my cham could OD on vit A?
https://www.chameleonforums.com/vitamin-scares-me-12395-post117713/#post117713
Found an answer, thank you search button *smacks forehead*.
Nicodemayo
Avid Member
I haven't seen any scientific journals concerning the chameleons converting beta carotene, but id love to see one, so maybe someone could chime in with someplace to look at that information...
Well, in that case, should I slow down with the carrots?
sandrachameleon
Chameleon Enthusiast
Carrots wont hurt anything. I use them and dandelion (also high in beta carotene) plenty. The Sweet potatoes are also good. But it couldnt hurt to add other things from time to time: Squash, orange, mustard greens, pomegranet, collard greens, kale, romaine, apple, alfalfa sprouts....
If you're interested in reading other posts regarding Vitamin A, here are some of the ones I found most interesting:
https://www.chameleonforums.com/food-thought-12472l
http://web.archive.org/web/200605020...Vitamin.A.html
https://www.chameleonforums.com/carrots-vit-23572/chame...nt-want-21534/
https://www.chameleonforums.com/carrots-vit-23572/serio...tml#post199819
If you're interested in reading other posts regarding Vitamin A, here are some of the ones I found most interesting:
https://www.chameleonforums.com/food-thought-12472l
http://web.archive.org/web/200605020...Vitamin.A.html
https://www.chameleonforums.com/carrots-vit-23572/chame...nt-want-21534/
https://www.chameleonforums.com/carrots-vit-23572/serio...tml#post199819
merumontanus
Avid Member
Hey Sabrina,
You have asked the million dollar question among chameleon enthusiasts, and as Ryan mentioned, a search on this forum will provide you with plenty of entertainment for the night. There is enough controversial evidence for some people to take to either side passionately, and the anecdotal stories on both arguments are plentiful.
Here is one abstract (involving renowned herpetologist Dr. Gary Ferguson):
"Insects are known to be poor sources of preformed vitamin A, leading to the speculation that insectivorous species, including reptiles, may be able to convert carotenoid precursors to meet dietary requirements for this nutrient. This study was conducted to indirectly evaluate carotenoid and vitamin A metabolism in the panther chameleon (Furcifer pardalis). Eggs were obtained from females in Madagascar that were yolked either early or later in the breeding season, and carotenoid (- and -carotene, cryptoxanthin, lutein/zeaxanthin, and lycopene), vitamin A, and vitamin E concentrations were measured in egg contents in early, middle, or late embryonic development. An overall trend of decreased nutrient concentration as eggs matured (from egg period 1 (yolks) to egg period 3 (embryos)) was seen within both clutch groups. The season of clutch deposition was a significant influence on egg weight, -carotene, and lutein/zeaxanthin concentrations, but on no other nutrients. Chameleon yolks contained considerably higher levels of carotenoids than levels previously reported from two viviparous lizard species, and -carotene concentrations were of the same magnitude as reported in grazing tortoises. -Carotene and -cryptoxanthin were the predominant carotenoids in yolk and embryos, comprising about 95% of total carotenoids detected. Measurable concentrations of retinol at all stages of egg development in the chameleons suggests effective conversion from carotenoid precursors, with concentrations similar to those measured in other lizard eggs. Information from eggs obtained in native habitats may provide baseline data on nutrient interactions to improve and optimize captive dietary management; preliminary data suggest that micronutrient environments may vary over the protracted breeding season, with possible implications for embryo health and survival. Zoo Biol 21:295-303, 2002. © 2002 Wiley-Liss, Inc."
During an interview in 2008, Dr. Ferguson had this to say about the subject:
"I don’t know why the carotene in carrots couldn’t be converted. It could be that other carotenes in the guts of wild plant-eating insects can be. It could also be why panthers sometimes occasionally eat lizards and nestling birds, which should be a good source of retinol. I think it is a good idea to feed panthers large pinkies or small lizards, such as anoles, occasionally, if they will eat them. There indeed needs to be more study on this subject."
I have had the pleasure of meeting and talking with Dr. Ferguson many times (worked closely with his colleague, Dr. Gehrmann in a zoological setting), and I can tell you that if anyone knows anything about this subject (as well as D3 synthesis) it is he. Still, he admits that much more research must be done, and since his work primarily focuses on pardalis, it wouldn't surprise me if the answer to the topic differed among taxa.
Having personally dealt with varying degrees of hypovitaminosis A in chameleons, and having also seen the rapid effects of careful and systematic dosing of preformed vitamin A as an attempt to reverse of the condition, I stand on the argument that it is more likely that chameleons, at least the many species of montane, ovoviviparous chameleons I have kept over the years, do not make effective use of carotenoids in the conversion of vitamin A, and thus require, at least in captivity, of careful supplementation of pre-formed vitamin A. This is important because vitamin A, apart from the dangers in overdosing, may in fact have adverse effects in the synthesis of vitamin D3, and ultimately, in metabolic functions, so any administration of pre-formed vitamin A should be made very carefully and ideally, under highly controlled situations (and a vet).
Dave Weldon has written extensively about this subject, and has a fantastic perspective on the subject from the use of silk moth larvae. Perhaps he'll chime in if he sees this...
Cheers,
Fabián
You have asked the million dollar question among chameleon enthusiasts, and as Ryan mentioned, a search on this forum will provide you with plenty of entertainment for the night. There is enough controversial evidence for some people to take to either side passionately, and the anecdotal stories on both arguments are plentiful.
Here is one abstract (involving renowned herpetologist Dr. Gary Ferguson):
"Insects are known to be poor sources of preformed vitamin A, leading to the speculation that insectivorous species, including reptiles, may be able to convert carotenoid precursors to meet dietary requirements for this nutrient. This study was conducted to indirectly evaluate carotenoid and vitamin A metabolism in the panther chameleon (Furcifer pardalis). Eggs were obtained from females in Madagascar that were yolked either early or later in the breeding season, and carotenoid (- and -carotene, cryptoxanthin, lutein/zeaxanthin, and lycopene), vitamin A, and vitamin E concentrations were measured in egg contents in early, middle, or late embryonic development. An overall trend of decreased nutrient concentration as eggs matured (from egg period 1 (yolks) to egg period 3 (embryos)) was seen within both clutch groups. The season of clutch deposition was a significant influence on egg weight, -carotene, and lutein/zeaxanthin concentrations, but on no other nutrients. Chameleon yolks contained considerably higher levels of carotenoids than levels previously reported from two viviparous lizard species, and -carotene concentrations were of the same magnitude as reported in grazing tortoises. -Carotene and -cryptoxanthin were the predominant carotenoids in yolk and embryos, comprising about 95% of total carotenoids detected. Measurable concentrations of retinol at all stages of egg development in the chameleons suggests effective conversion from carotenoid precursors, with concentrations similar to those measured in other lizard eggs. Information from eggs obtained in native habitats may provide baseline data on nutrient interactions to improve and optimize captive dietary management; preliminary data suggest that micronutrient environments may vary over the protracted breeding season, with possible implications for embryo health and survival. Zoo Biol 21:295-303, 2002. © 2002 Wiley-Liss, Inc."
During an interview in 2008, Dr. Ferguson had this to say about the subject:
"I don’t know why the carotene in carrots couldn’t be converted. It could be that other carotenes in the guts of wild plant-eating insects can be. It could also be why panthers sometimes occasionally eat lizards and nestling birds, which should be a good source of retinol. I think it is a good idea to feed panthers large pinkies or small lizards, such as anoles, occasionally, if they will eat them. There indeed needs to be more study on this subject."
I have had the pleasure of meeting and talking with Dr. Ferguson many times (worked closely with his colleague, Dr. Gehrmann in a zoological setting), and I can tell you that if anyone knows anything about this subject (as well as D3 synthesis) it is he. Still, he admits that much more research must be done, and since his work primarily focuses on pardalis, it wouldn't surprise me if the answer to the topic differed among taxa.
Having personally dealt with varying degrees of hypovitaminosis A in chameleons, and having also seen the rapid effects of careful and systematic dosing of preformed vitamin A as an attempt to reverse of the condition, I stand on the argument that it is more likely that chameleons, at least the many species of montane, ovoviviparous chameleons I have kept over the years, do not make effective use of carotenoids in the conversion of vitamin A, and thus require, at least in captivity, of careful supplementation of pre-formed vitamin A. This is important because vitamin A, apart from the dangers in overdosing, may in fact have adverse effects in the synthesis of vitamin D3, and ultimately, in metabolic functions, so any administration of pre-formed vitamin A should be made very carefully and ideally, under highly controlled situations (and a vet).
Dave Weldon has written extensively about this subject, and has a fantastic perspective on the subject from the use of silk moth larvae. Perhaps he'll chime in if he sees this...
Cheers,
Fabián
dodolah
Retired Moderator
that's correct.
Don't quote me a 100% on this. But, if I have to guess, one source would probably come from some insects that consume mammals blood.
There is trace of preformed vit A as well in commercial silkworm chow.
plus, chameleon in the wild probably have opportunities to eat some lizards or small rodents or birds.
merumontanus
Avid Member
You're welcome. I think what he's saying is that there may be certain carotenoids in the wild that chameleons may be able to convert, or it may be that simply, some insects (or other animals) may contain enough pre-formed vitamin A to make the difference. The problem lies in that we do not offer our animals the variety of prey they would usually get in the wild, and the gut-loads we provide our insects may or may not closely resemble the nutritional content of wild insects, which as you might imagine, must vary from the arid, coastal, habitat of calyptratus in the Saudi Arabian peninsula, to the cloudy rainforests of Madagascar and Mt. Kenya.
Here is another article on the subject (published also on the Animal Planet website):
Chameleons: Signs, Treatment, and Prevention of Vitamin A Deficiencies
Again, the metabolic implications of pre-formed vitamin A on D3 synthesis cannot be over-emphasized, so you must take into account the frequency of vitamin A supplementation, so as to not antagonize vitamin D conversion, and therefore not suddenly end up with a chameleon with metabolic bone disease even though you may be providing enough UVB and/or dietary D3.
Fabián
Docility
New Member
almost any insect that wants a taste. you remember it says "Could be" not there is.
at any rate i was gut loading with a Vitamin A enriched diet, and im pretty sure my guy suffered from a sever lack of vitamin A. The fact the animals are primarily plant/bug eater, and only eat the small animals upon need. at least to me says they cant generate, or cant generate even a decent amount of Vitamin A, and supplement their selves by doing this.
at any rate i was gut loading with a Vitamin A enriched diet, and im pretty sure my guy suffered from a sever lack of vitamin A. The fact the animals are primarily plant/bug eater, and only eat the small animals upon need. at least to me says they cant generate, or cant generate even a decent amount of Vitamin A, and supplement their selves by doing this.
Syn
Avid Member
Vitamin A hurts D3 absorption? So per chance dubia roaches can convert beta carotene to Vit A, would it be a large enough amount to do any damage?
Just making sure I'm understanding this, because I've read something as one thing and it has meant another in the past, so I don't want to take any chances.
Fabian I will take a look at that website tomorrow, I've read through some of it and I won't be able to finish reading it (and fully understanding it) by the time I have to go to bed. Thanks again. You find some great reading.
Just making sure I'm understanding this, because I've read something as one thing and it has meant another in the past, so I don't want to take any chances.
Fabian I will take a look at that website tomorrow, I've read through some of it and I won't be able to finish reading it (and fully understanding it) by the time I have to go to bed. Thanks again. You find some great reading.
Docility
New Member
Vitamin A hurts D3 absorption? So per chance dubia roaches can convert beta carotene to Vit A, would it be a large enough amount to do any damage?
Just making sure I'm understanding this, because I've read something as one thing and it has meant another in the past, so I don't want to take any chances.
Fabian I will take a look at that website tomorrow, I've read through some of it and I won't be able to finish reading it (and fully understanding it) by the time I have to go to bed. Thanks again. You find some great reading.
the amount of preformed A a dubia could hold is slim to none. think how tiny their stomach is, and how little they actually need to convert to sustain their life
