11/25/2022
Author of this write up is McDonald
QUICK(ish) UVB & SUPPLEMENTS RUNDOWN
For some reason supplements have been a hot topic lately, with many members asking about them and expressing frustration when faced with the many different supplement and UVB options and different sets of recommendations.
Hopefully this post provides some clarity. I'm not a scientist, I don't know everything, but here's what I've come to understand in a nutshell.
UVB AND SUPPLEMENTS WORK TOGETHER. Especially regarding D3 and Calcium.
Calcium facilitates growth and egg development, and also powers muscle and nerve function. Vitamin D3 allows them to metabolize the calcium from their diet, so it can be utilized in those areas and functions. Without D3, the calcium passes through their system unused, and if the deficiency isn't rectified quickly, their body begins stealing it from their bones, because it prioritizes reproduction, muscle and nerve function over bone density. This calcium deficiency as a disorder is called Metabolic Bone Disease, or MBD for short. It's painful, permenantly disfiguring, and ultimately fatal if not stopped in time.
MBD prevention is key!
When exposed to enough UVB, chameleons (and a whole slew of other animals, including us) create Vitamin D3 in their skin, which is then used to metabolize calcium. The creation of d3 stops on its own once they have enough.
A study conducted on panther chameleons shows that chameleons (and probably many other reptiles) can sense how much d3 they have in their system, and will adjust their basking behaviour in accordance to how much d3 they need. As keepers we choose their main d3 source. UVB or Diet (supplements).
---UVB for D3 (most natural, self regulating)
We either house them outdoors, where uvb is reliable and plentiful, or house them indoors under a UVB light that creates a high enough UV Index for full d3 synthesis, occasionally providing small amounts of dietary d3 to account for the gradual decrease in UVB output inherit to all artificial uvb lights. We can use Solar Meters 6.5 to measure the exact UVI in the basking spot of their enclosure, helping ensure they have access to enough UVB to make their own d3.
---Supplements for d3 (guess work, outdated)
Yes, it's possible to keep a chameleon alive without UVB, by giving them supplements that contain d3. This is what indoor keepers had to do before adequate UVB tech became available and safe to use. This is far from ideal because by forcing them to be dependant on d3 from their diet, we are overriding the natural process and replacing it with guess work. Without blood tests and biopsies we can't measure how much d3 or calcium they have in their system, so our only way to know if it's too much or not enough is to wait the weeks or months it takes for the outward signs of health problems arise. By then, you're looking at irreversible damage, and lots of unnecessary suffering. Not enough d3 leads to MBD. As a fat soluble vitamin, their body stores excess D3 instead of passing it through their excrement. Too much can cause the calcium in their body to do things we don't want it to, like calcify soft tissue, and damage their organs over time.
VITAMIN A
Vitamin A is primarily essential to eye health; symtoms of VitA deficiency usually include eye problems but can also affect tongue function. Poor eyesight can limit their ability to eat on their own, and makes them more susceptible to injuries and falling. Poor tongue function also impacts eating, but can also lead to injuries requiring emergency amputation or even euthanasia. Because chameleons can't convert Vitamin A precursors, like beta carotene, into vitamin A, the multivitamin we choose needs to contain sources of preformed vitamin A, like retinol. Keepers who rely on a multivitamin for vitamin A and backup d3, usually only use it once every 2-6 weeks depending on species and diet. Vitamin A is also a fat soluble vitamin, the excess is stored, and hypervitaminosis A can cause health problems over time as well.
CALCIUM GUTLOADING AND VARIETY
Calcium is mostly to offset the phosphorus content in crickets, which are a primary staple for most keepers. Many feeder insects have lots of calcium, and a more balanced calcium : phosphorus ratio. Offering a large variety of feeder options and carefully formulating your gutload recipes can ultimately negate the need to use powdered supplements. However this method can be an extensive endeavor, so its not always feasible for everyone.
Most detailed and updated care guides outline a system of husbandry that combine different aspects of husbandry to meet chameleon needs in the safest way. So when looking for a uvb or supplement schedule, make sure you don't pick and choose different recommendations from different care guides, as the pieces you choose may not fit together properly.