Not giving Vitamin A should scare you more.
There are more cases of hypovitaminosis reported than there are of hypervitaminosis.
Does the calcium supplement scare you?
What study do you follow on that dosage?
How about with D3?
-Brad
The toxicity levels of vitamin D3 are much higher than those of vitamin A. As for calcium, there are many more uses in the body and again has a very minimal chance of reaching "toxic" levels. As said previously, reported hypervitaminosis (for any of the fat-soluble vitamins) is uncommon. However, I'd be challenged (but not impossible) to find a person who could immediately identify signs of hypervitaminosis. I would not hesitate to assume many chameleons have been misdiagnosed. With vitamin A, small frequent doses do add up. Generally, animals (and people) have cravings when they require any specific vitamins or minerals. In the wild, it's likely that chameleons will dine on blood-sucking insects or small vertebrates. As we have removed these animals from the wild, there is no way of knowing when they want their meal to be a little lizard. There is not likely going to be significant amounts of any vitamin in these meals and the frequency of these meals is unknown (but it's likely not an everyday thing because we have seen many breeders that have successfully raised chameleons without vit A supps). Therefore, we really should supplement at least a little bit.
I'd love to really study these animals in their habitat for several seasons (you know, like Jane Goodall of the Chameleon World) to better understand their natural nutritive habits.
You've got to understand that when you remove any animal from their natural habitat (no matter how well you emulate it) changes in diet need to be made to appropriately accommodate the changes. There just isn't necessarily one correct way to raise them, and with minimal official clinical trials provided there aren't even necessarily ways that are better than others (except for trial and error, and perpetually successful breeders).
I wouldn't ever claim to know exactly how much (human RDAs are just estimates also and are ever changing as new research is revealed) vitamins and minerals promote optimal health, but I DO know that vitamins are NOT treatments. In fact, we have come a long way since the days that we thought vitamins and minerals were medications for disease. THEY ARE TO BE USED FOR PREVENTION AND MAINTENANCE OF OPTIMAL HEALTH. Key words: prevention and optimal. Keep in mind that animals and humans, both, can live long lives with minimal supplementation of vitamins and minerals. But research shows that those who consume certain amounts of vitamins and minerals longevity increases and incidence of illness decreases.
SO, that being said, again there is no set limits for chameleons, but please consider using vitamin A as an infrequent addition to a regular diet because the negative effects of over-doing it (with vitamin A) are worse than the negative effects of under-doing it.
-Chris (& Stacey esp. about the Jane Goodall thing)
