Understanding Calcium & D3: Why Your Reptile Needs UVB Lighting and Supplements
We talk about calcium like it’s the only thing your reptile needs. Whenever you’re planning your pet’s diet, calcium content is just about as important as protein or fat. And because most insects have less calcium than your pet needs, you normally have to dust them with calcium powder. Calcium this, calcium that. But why is calcium so necessary, and do all reptiles need it?
In this article, we’ll talk about what calcium does for your reptile pet, and the other steps you need to take to make sure they get enough of this vital nutrient.
Why Do Reptiles Need Calcium?
Before we get into the nitty gritty, let’s explain why calcium is important in the first place. Calcium is a vital nutrient that serves as the building block for your reptile’s “hard parts”; their bones, teeth, and shell.
It’s also essential for making nerves fire and muscles contract (especially the heart). It prevents blood clots and is necessary for producing hormones, which regulate the body’s systems.
So, as you might have guessed, trying to go without a vital nutrient is a bad idea. For insectivorous pets, this means dusting your feeders. Luckily, carnivores like ball pythons get all the calcium they need from the bones of their prey.
Risks of Low Calcium
Specifically, the main risk of low calcium in reptiles is metabolic bone disease (MBD), which manifests itself as brittle bones that break easily. It can also cause paralysis, muscle weakness, and tremors. These are all symptoms of the muscles not having calcium to contract and release.
Beyond that, low calcium can lead to growth deformities like rubber jaw, which is also common with shells. Other skeletal issues can include spinal kinks, and bowed legs.
Suffice it to say that calcium deficiency is bad news, and something you should avoid at all costs.
Normally, we try to avoid calcium deficiency by dusting our feeders with calcium supplement, which boosts their dietary intake. But there’s another key component of calcium delivery: light.
How UVB Makes Calcium Accessible
As it turns out, giving your pet all the calcium in the world won’t do them any good if they don’t also have UVB light. That’s because UVB allows your pet to synthesize vitamin D3 in its body. Without vitamin D3, reptiles can’t absorb any of the calcium they get in their diets.
So even if your pet is hitting its dietary calcium needs, it won’t be able to use any of it. In a way UVB/vitamin D3 is just as important as calcium for a reptile. In the same way you make sure your pet gets enough calcium, you need to make sure they get enough D3 to absorb it all.
Does My Pet Need UVB?
Short answer: yes. There is some argument as to whether primarily nocturnal animals like pythons and crested geckos need UVB. And while they don’t rely as heavily on UVB to synthesize vitamin D3, remember that your pet is not a wild animal.
In the wild, animals are getting everything they need from nature. In your house, you’re trying to replicate the natural environment as closely as possible. So while you might be able to get away with not giving a crested gecko UVB, you really should make sure they’re getting at least a low dose of UVB in their enclosure.
If you don’t, you may be stopping them from getting something they need as part of their daily life, which could lead to issues down the line.
How Much UVB Does My Pet Need?
This is a much better question, and it depends on your pet’s life history (where it lives naturally, what its habits are, and what its physiological demands are). UVB needs vary a lot between species, which makes sense because a desert dwelling species is going to get a lot more sun than something that lives on the rainforest floor.
On the high end, you have your desert species, meaning bearded dragons, collared lizards, and Russian tortoises. These species need a bulb with at least 10% UVB, usually 10-14 hours per day.
In the middle, you have tropical species and some nocturnal species, which don’t need as much. This category includes things like leopard geckos, ball pythons, and green anoles. These species need 5-8% UVB, depending on which. These species should still be set up with a basking spot at one end of the enclosure, which stays light for 10-12 hours per day.
On the low end, you have species like crested geckos and some snakes, which get more of their UVB in their diets. However, it’s still wise to have a 5% UVB bulb in the enclosure so that they can get more D3 from light.
Setting Up Your Pet's Enclosure for UVB
In general, your reptile enclosure should include a basking spot where your pet can top up on UVB and warm up when it needs it. The UVI (Ultraviolet Index) in this spot will vary depending on your pet.
Bearded dragons (a high UVB desert species) will need a UVI of 4.0-6.0 on their basking rock. Chameleons need a little less, being a forest species that is accustomed to shady environments.
You can set them up with an area in the enclosure with a UVI of 3.0 or so. Ball pythons need even less, and primarily bask for warmth. The UVI should be between 1.0 and 3.0 on their basking rock.
The other major factor is picking the right UVB bulb. Using the guide above, make sure your pet is getting enough (not too little, not too much) UVB from their light.
Normally, UVB bulbs come in a 5% and 10% option. Some go even higher, for species that need a lot of UV like bearded dragons.
If you have a pet with low UVB requirements, you can buy a bulb with 5% UVB and play with the angle and distance from the basking area to tweak the UVI. If you need to increase the heat, you can always add another bulb to make sure your pet gets what it needs.