You can't beat the sun for UVB

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jaizei

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Will said:
Ummmmm you too might want to hone your reading skills, that study does in fact purport that dietary D3 IS effective, at least for green iguanas.

Will

That is what I said. Something something reading skills :)
 

Tom

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Will said:
Just to mess with you Tom, openly and without ill-intent, here is an article (same format) suggesting coil bulbs are good, but still not as good as sunlight.

When messing with me makes me better informed, please mess away...

To be clear, my argument with the coil bulbs has nothing to do with whether or not they are effective for UV delivery. I don't know the answer to that one way or the other. My recommendation to not use them is based on the frequency with which I personally see them cause eye damage to tortoises and other reptiles.


jaizei said:
Study showing that D3 has an effect.
www.anapsid.org/pdf/jody-hibma-uvb.pdf

This is the study that your buddy posted several months ago. It studies growth, not dietary D3 absorption. Nowhere in this study were blood levels of D3 tested.

Will, would you have a look at this and correct me if I'm wrong?
 

Kapidolo Farms

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Thanks for the prompt to re-read that study yet again Tom. The inference is strong, but it is inference, not direct evidence in the form of measured blood values.

That is a tricky thing to parse out. The set up is good. They used good controls. UV light and dietary D3, UV light and no dietary D3, no UV light and no dietary D3, and no UV light with dietary D3.

That level of combined and single variables allows a strong inference, but you are right, not direct evidence.

That the lighting measured as not valuable and the dietary measured in as valuable follows a great preponderance of anecdotal observations. It is strong enough for me to believe that dietary D3 is an effective form of that nutrient fulfilling that paradigm I talked about in another thread. That you can provide a benefit of a wild type life inside. It's just more complicated.

The study "needed" is one that will show some ration and form of dietary D3 that emulates the D3 in the blood from tortoises in their natural exposure to sun.

I have a sneaking feeling too, that one in 10, or one in a hundred (some part of the population)of tortoises does not have some link in the chain of needed processes, the ability to metabolize dietary D3 as if it was from sunlight.

Males have different requirements than females, D3 at certain levels also act as a hormone for reproduction. I would guess that's related to seasonal temps and the duration of basking each day. In the spring temps are lower, so basking would be greater, so those individuals at that time of the year would have elevated D3 in their blood, as a default result of increased basking.

As for messing with you Tom, that was not fair in the sense that I do understand the objection with coil type bulbs, and I do realize that is different than what the point of the slider experiment was about. Still it is ironic, and I can see people construing that the use of coil bulbs for UV properties of bulbs used by "scientists" would validate that bulb type use otherwise - which it clearly would NOT indicate.

Again, the sun is a simple means to an end, getting access to UV radiation, such that your pet will have normal and healthy growth. However I do absolutely find the anecdotal evidence that dietary D3 is effective. I'd like a home test kit for that blood value, so I could check seasonally and adjust the amount of supplementation up or down for the age, and sex of the animals. I don't see this as something coming anytime soon, if at all.

Further consideration that should also be noted. No tortoise is a 'perfect' herbivore. They consume 'meat' both intentionally and incidentally all the time. Grocery greens are clean of insects. Wild source greens are often loaded with insects, and I have seen captive tortoises outside consuming huge loads of insects as incidental to eating plants. I would not presume to think they 'intend' to eat the insects, but that is possible too. So that too, would be a means in which wild and outdoor tortoises would be consuming animal products as food, and therefore getting dietary D3. I think that pathway is corrupted in some tortoises as individuals, as stated earlier in this post.

Will
 
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