Taterbug
BD.org Addict
This came across my dash on tumblr today and thought it might help some folk here too. TheExoticVet has a pretty good blog too, if you like following that sort of thing. Some bit are bolded (by me) for emphasis.
I’ve gotten a few questions about calcium supplements in reptiles and will hopefully clear up some of the confusion. Also, if you have a question for me, please send me an inbox message and don’t just reply to a post. I sometimes don’t see the replies and will miss the question.
Calcium is necessary for making and maintaining bones and has other functions in the body as well. Calcium is obtained through the diet and absorbed through the intestines. Vitamin D is what allows the intestines to absorb the calcium for metabolism. If vitamin D levels are too low, it does not matter how much calcium is ingested, reptiles cannot use it.
Reptiles produce all the vitamin D they need within their own bodies. UV light, specifically UV-B stimulates production of vitamin D. When they have enough vitamin D, they automatically stop making more. So they bask in UV rays to produce vitamin D, they ingest calcium which is “unlocked” by the vitamin D.
Back in the old days of reptile keeping we knew reptiles needed vitamin D and that they needed UV light to produce it but we didn’t have the technology to safely and adequately produce UV-B. Someone came up with the idea of providing vitamin D along with calcium as a supplement. Sadly what ended up happening was that reptiles were overdosed with vitamin D and a good portion of them ended up in renal failure. Now we have UV lights that produce the needed UV-B so there is no reason to supplement vitamin D anymore. Because so many keepers were used to supplying vitamin D it continued to be sold and it is yet another of those pet keeping myths that are constantly perpetuated because people keep buying the products which makes the companies produce more.
So if you dust your reptile’s food items with calcium powder every other feeding or so and provide adequate levels of UV-B, they will have proper calcium and vitamin D metabolism. There is no reason to supplement vitamin D and it is not safe to do so. There are other vitamins and mineral supplements out there that can be given once every week or so in place of calcium. One of the more important vitamins is vitamin A. Often this is sold as a beta-carotene which the reptile should convert to vitamin A. The problem is many species cannot metabolize beta-carotene into vitamin A, so it is better to just have vitamin A pre-formed in the supplement.
In reality, we only need these supplements because we do not or cannot replicate the natural environment of reptiles in captivity. Theoretically if you kept a reptile in the perfect habitat with the correct humidity, temperature, UV levels and fed it a balanced, varied diet it wouldn’t need supplements. However reptiles tend to get less than ideal care. Even those that are cared for properly get less than ideal diets. Mass produced crickets and meal worms are not that nutritious. Gut loading them helps and dusting them with supplements helps as well.
