# Research



## Tim/Robin (Dec 21, 2009)

There have been several references of late to research on numerous topics. One very recently was on the topic of UVB. Several have mentioned basing their decision for use of UVB on research. This brings to mind many questions. 
Any one who has ever taken any college level research and statistics courses learns that research has to be evaluated for validity. Statistics in and of itself is basically worthless if not evaluated and placed in context. Again, if you have taken a statistics class you know you can utilize many different statistical tests to "prove" just about anything you want. You even can skew the results to again, "prove" anything. Just because something is "published and labeled research" does not mean that it is true.
To be a valid research many things must be considered. Some examples would be, can the research be replicated by anyone and the results be the same? Is the research biased, or has it been influenced by something external? When critiquing research, one always raises an eyebrow when the one conducting and publishing the research is a company that sells the product researched. A perfect example of this is drug companies. They do all kinds of research and publish the findings that benefit them and the success of their product, meaning revenue. Another question, has the research been conducted by non-biased or non-related parties?
As for statistics, one question always arises, are the findings statistically significant? Meaning, finding that a new medication helps one out of 10,000 tested is not statistically significant.

I (Tim) admit that I have not looked in depth at the "research" that has been mentioned numerous times about UVB. I invite those that have looked at it and base their advice and opinions on such research to look closely at the findings of such "research". Is there validity to the research? Were all biases eliminated? Are the findings statistically significant? Has the research been conducted by some one not affiliated with the product/products tested? Has the research ever been reproduced with similar findings? Then please share your opinions and your analysis of that research.

Remember, just because a manufacturer publishes "their findings" does not mean it is valid research. And so, recommendations based on those findings may not be valid either. That manufacturer is only going to publish findings that will benefit them. Additionally if the manufacturer is the one funding the research, again is it valid research?

An interesting example of recommendations based upon research will follow.
Lidaocaine has for years been the drug of choice for a post cardiac arrest patient. They get started on a Lidocaine drip fairly quickly. Lidocaine is an old medication, been around a long time. Fairly recently a new drug (Amiodarone) has been tested and approved for the same purpose. The American Heart Association bases all its algorithms and recommendations on research findings. Because Amiodarone is new and lots of research has been funded by the drug company that makes it, it now is the "recommended" drug by the AHA. However, this does not mean it is any better or more effective than Lidocaine. It simply means more recent research is available. No one wants to fund new research on such an old medication as Lidocaine. There is no money in it, therefore it has gone by the wayside in recommendations, but is still very widely used. 

The point of this example is research is not perfect and does not always point to a perfect solution. Again, any research needs to be carefully analyzed for validity.

WOW, that was a very lengthy post. Hopefully some will find it useful and see my point.


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## Stephanie Logan (Dec 21, 2009)

This is one of my dad's favorite jokes: "Have you heard about the 6-foot tall statistician? He drowned crossing a river with an average depth of 5 feet." 

I took a course called "Tests and Measurements" as an undergrad. It was fascinating and "stuck" better than most of the classes I took all those years ago. We studied several of the concepts you outlined above.


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## elegans (Dec 21, 2009)

I guess that I am showing my age, but the best one ever has still got to be. "There are Lies, Damn Lies and Statistics!" LOL Yeah about that???? Nothing is ever true until there is a tool to measure it, and then you have to buy it from "Snap On" for about 1000 times what it is worth. At least for a few years, till the patent wears off. Snap! Best wishes Douglas


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## Madkins007 (Dec 21, 2009)

Tim- I've been playing in the UVB area for a while now. I am by no means a scientist and often have to work to figure out what the article is saying. What is catching my interest now is the work by people like William H. Gehrmann, who is looking at what specific wavelengths different bulbs are putting out, and how much pro-D3 the bulb converts to pre-D3.

As far as I can tell, this is not being funded by a lighting company, and his research is valid enough that he wrote the lighting part of Dr. Douglas Mader's "Reptile Medicine and Surgery" book. What excites me is that this version of the research SHOULD be more translatable to what the bulb does in reptile skin.

Of course, none of this answers the bigger questions, like how much UVB or vitamin D3 does a tortoise need, how much can it get from diet and D2, etc. but it does point out that just saying UVB is not adequate- you need to know how much of the output is on the furthest part of the UVB spectrum, because the stuff on the near part is not going to help much.

There are two things that drive me crazy with research-

1. Half-done research that results in statements like 'they need UVB' and thus thinking that a typical UVB bulb is all you need, and

2. The annoying tendency of research to drive more research- the fact that it so often does not really answer anything but makes you dig even deeper or go elsewhere for more.


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## Meg90 (Dec 21, 2009)

I just want a system for the D3 method. As in, use ___ tsp of Ca powder with D3 per 50g of tortoise every second day (or daily, weekly etc)

I think its ignorant to tell someone "just grab some Ca powder w/ D3 and you'll be fine" Because how MUCH do you use, and how often? Does the dosage differ between species? Do Red Foots need less Calcium than Greeks? Sulcatas?

I have also been told that improperly dosed, D3 has the potential to become toxic as it is stored in the fat when supplemented. 

I'd love to compare the daily blood Ca levels of a (say) Greek tortoise under a 100W MVB, to one in an outdoor environment and lastly, to those of a tortoise being dosed only with D3. Its the blood Ca level that determines whether or not they need to start leaching Ca from their shell and bones, just like in humans, and its Vitamin D that allows for the absorption of Ca itself. If the D3 works like everyone thinks it does, it should be comparable and only marginally different to the bulb or the actual sun.


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## Tim/Robin (Dec 21, 2009)

Meg90 said:


> I just want a system for the D3 method. As in, use ___ tsp of Ca powder with D3 per 50g of tortoise every second day (or daily, weekly etc)
> 
> I think its ignorant to tell someone "just grab some Ca powder w/ D3 and you'll be fine" Because how MUCH do you use, and how often? Does the dosage differ between species? Do Red Foots need less Calcium than Greeks? Sulcatas?
> 
> ...



Those are all good questions. Get some one to fund it and do the research. It would be a daunting project and huge! The fact is, not many are doing research on tortoises. There is no money in it, except by the product manufacturers. Once actually setting up such a research project, I think the variables would be far too many. It would not be as simple as circulating Ca levels. How would you ever regulate Ca consumed in food? It would be impossible to regulate what each tortoise in the study chooses to eat at any given time. How would you regulate how much exposure to the sun or UVB each tortoise gets in a single day? There are just way too many variables to ever set up an accurate study.

I think it would be impossible to come up with dosages. First of all, the D3 is added to the calcium powder, how would you even guess how much they are actually eating? There will never be a clear cut X dosage. I just don't see that ever happening. The best we can do is base decisions on experience of others. It will not be as scientific or measureable, but success is success, and that may be all we ever get in this hobby. It is not funded like medical research.


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## Meg90 (Dec 21, 2009)

The food part would be easy. The could just be fed a commercial diet, each the same amount. It would all have to be recorded as well, including how much food was left over on any given day if the tort was not hungry. UVB length would have to be identical to day length, compensating for a change in seasons. I would try for a location that is warm enough for a tort year round outside. 

Powder doses could be recorded first. Once the established number of the Blood Ca level in a healthy tort is known and recorded, I would try to find a dosage of D3 that came up with the same number. I would dose a tortoise with a certain amount, say 1/2 tsp daily to start with, and see how the blood Ca is after a weeks time of steady dosages. If its close to what the norm is, then I would continue with that amount over the course of the study and see how it holds up over time.

But Tim/Robin, as you've said, there are a TRILLION variables to work with, and not alot of people willing to get the headache. So how can it be considered responsible to condone or recommend this method to a new keeper when it has never even remotely been proven to be healthy, or even work at all?

Sadly most of the torts that live off of D3 powder instead of UVB lights would have to be studied via autopsy do find bone density and shell thickness and porousness. So even if there are those out there that say that their tortoises are healthy, there is really no definitive way of knowing until after death.


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## -EJ (Dec 21, 2009)

I've said time and time again what you have said... This is why we have peer reviewed publishing... to get a concensus.

Statistics exists because biology is one huge grey area. Using numbers it is supposed to give you the most probable. There will rarely be a specific/definitive answer.

How on earth would you quantify the benefits of UVB? There is one person who might have come close... Dr. Gehrman... and I'll be willing to be he would even admit that his findings are still anecdotal but with stong evidence. He is not associated with any product as far as I know.






Tim/Robin said:


> There have been several references of late to research on numerous topics. One very recently was on the topic of UVB. Several have mentioned basing their decision for use of UVB on research. This brings to mind many questions.
> Any one who has ever taken any college level research and statistics courses learns that research has to be evaluated for validity. Statistics in and of itself is basically worthless if not evaluated and placed in context. Again, if you have taken a statistics class you know you can utilize many different statistical tests to "prove" just about anything you want. You even can skew the results to again, "prove" anything. Just because something is "published and labeled research" does not mean that it is true.
> To be a valid research many things must be considered. Some examples would be, can the research be replicated by anyone and the results be the same? Is the research biased, or has it been influenced by something external? When critiquing research, one always raises an eyebrow when the one conducting and publishing the research is a company that sells the product researched. A perfect example of this is drug companies. They do all kinds of research and publish the findings that benefit them and the success of their product, meaning revenue. Another question, has the research been conducted by non-biased or non-related parties?
> As for statistics, one question always arises, are the findings statistically significant? Meaning, finding that a new medication helps one out of 10,000 tested is not statistically significant.
> ...


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## Tim/Robin (Dec 21, 2009)

Meg90 said:


> The food part would be easy. The could just be fed a commercial diet, each the same amount. It would all have to be recorded as well, including how much food was left over on any given day if the tort was not hungry. UVB length would have to be identical to day length, compensating for a change in seasons. I would try for a location that is warm enough for a tort year round outside.



That does not address how do you quantify the amount of Ca eaten in a given day? It also does not address how you plan on getting a uniform amount of UVB or sun exposure on each tort each day. It simply would be almost impossible. What about amount of time spent in shaded areas? 



Meg90 said:


> Powder doses could be recorded first. Once the established number of the Blood Ca level in a healthy tort is known and recorded, I would try to find a dosage of D3 that came up with the same number. I would dose a tortoise with a certain amount, say 1/2 tsp daily to start with, and see how the blood Ca is after a weeks time of steady dosages. If its close to what the norm is, then I would continue with that amount over the course of the study and see how it holds up over time.
> 
> But Tim/Robin, as you've said, there are a TRILLION variables to work with, and not alot of people willing to get the headache. So how can it be considered responsible to condone or recommend this method to a new keeper when it has never even remotely been proven to be healthy, or even work at all?



That is easy, base your decisions and recommendations off of success! That is really all we have and likely will ever have. Try something and monitor for effectiveness. I (Tim) am not anti-UVB. Our animals spend a lot of time outside as you all know. I simply know from our experience that good quality bone growth can be done with no indoor UVB exposure.


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## Meg90 (Dec 21, 2009)

That's where it differs for most keepers. Your outdoor setups were costly (and are stunning, I'd like to rent a room when you have an opening) but most people do not have those kinds of setups outdoors and when told they can skip the UVB for D3, that's what they do. No one says "BUT your tort should spend at least two months worth of days outdoors in the sun for it to be effective"

There are a TON of variables in the D3 method itself. Those being: the amount given, when it is given, the amount actually consumed, length of time spent under the actual sun, brand of supplement, age of supplement (we all know they can lose effectiveness if not used in a timely fashion) and the list goes on.

With the bulbs, there is a recommended wattage per species, a recommended changing time for the bulbs themselves, a specific length of time that they need to be running, as well as research on the wavelengths of the light to show their effectiveness.

Its one thing to say only use D3 and its another animal entirely to say use D3 and also house the animals outdoors as often as possible. I can't remember if you mentioned that to Merrit in his thread "hibernation oozing" but he has recently posted about building an outdoor enclosure a couple years down the road for his tort, and that he lives in an apartment complex that has mostly concrete outdoors, so it seems improbable that his tortoise will spend much time outside at all.


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## -EJ (Dec 21, 2009)

Can you explain this post in terms I might be able to understand?




Meg90 said:


> The food part would be easy. The could just be fed a commercial diet, each the same amount. It would all have to be recorded as well, including how much food was left over on any given day if the tort was not hungry. UVB length would have to be identical to day length, compensating for a change in seasons. I would try for a location that is warm enough for a tort year round outside.
> 
> Powder doses could be recorded first. Once the established number of the Blood Ca level in a healthy tort is known and recorded, I would try to find a dosage of D3 that came up with the same number. I would dose a tortoise with a certain amount, say 1/2 tsp daily to start with, and see how the blood Ca is after a weeks time of steady dosages. If its close to what the norm is, then I would continue with that amount over the course of the study and see how it holds up over time.
> 
> ...




even those that sell calcium do not have a precise amount. It will be a ratio based on a standard biological model... for mammals.

Good luck in you quest.



Meg90 said:


> I just want a system for the D3 method. As in, use ___ tsp of Ca powder with D3 per 50g of tortoise every second day (or daily, weekly etc)
> 
> I think its ignorant to tell someone "just grab some Ca powder w/ D3 and you'll be fine" Because how MUCH do you use, and how often? Does the dosage differ between species? Do Red Foots need less Calcium than Greeks? Sulcatas?
> 
> ...


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## Meg90 (Dec 21, 2009)

EJ, the above post was a musing. I do not know how to make it clearer? Perhaps you could point out the parts that are causing you trouble?


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## elegans (Dec 21, 2009)

I offer my tortoises as much sunshine as they can possibly get, plus I give them as many cuttle bones as they want to eat. This varies by species and by season. Now these numbers change and I do take a personal note of that. I do not qualify as any kind of authority so no worries there. I do offer a Cal + D-3 supplement 2 times a week on all of my "inside" guys. Seems like it has been working for the last 15 years for me, but maybe it is just me?


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## pyxistort (Dec 21, 2009)

So far, no one share the research or study about UVB usage for tortoise yet. I would like to see why it is must have to keeping tortoise. Is there any information about specific instruction to use UVB for tortoise?


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## fifthdawn (Dec 22, 2009)

I've taken both Statistics and Research Methods.

The only way to really know how much VitD a reptile need depends on how well you can control the Control Group. You only need as much D3 as there are calcium available. What we DONT need to know is how much a reptile needs. What we need to know is how much D3 a reptile need based its calcium intake on an average diet. You see the logic right? I'm gonna use 1g in this case, its probably high, you can pretend its mg or something. Hypothetically, if every 1g of D3 metabolizes 1g of calcium, then if a reptile isn't eattiing, you wouldn't need any sunlight. If the veggies your tortoise eats totals up to 3g, then youd need 3g of D3. This is under the assumption that reptiles convert all the calcium they can, which usually isn't the case, then you'd have to find the threshold.

As to finding the threshold, from what I remember, you don't usually use up all the calcium you consume even if there is enough D3 for all calcium metabolization.
The first thing you have to find out is if the "natural" converstion fo vitamin D is constant. The only way to find this out is controllin the amount of calcium the reptile takes. Excess calcium will be left in blood stream and eventually peed out if the body does not store all of it in bones. 

This is one way you can go at your experiment is to have a reptile consume a fixed amount of calcium then control for the amount of D3 it takes supplemented. 

For example, 1g of Cal with 0.5g of D3. Measure the calcium level in the pee. You need to see if that amount is enough to convert all of the Calcium. If it isn't, slowly increase the D3 level until you come close to how much is needed to convert 1g of Calcium. If its enough, then lower the D3 until you find calcium in pee, indicating you don't have enough D3 for full conversion.

Next, assuming 1g is a small amount, like I said earlier, I'm not sure, pretend is miligrams if g too high. Once you find out the calcium to d3 ratio in full conversion, you'd need to find the threshold. Remember, they don't use up all calcium it consumes. At one point, you'll reach a point where there is more calcium than their body needs. Increase 1g to 2g. Measure Ca in pee level. If you keep Ca to D3 constant, the 1g and 2g should not show up in the pee. Sooner or later, you'll hit the point where you find trace amounts of Ca in the pee. Then you've discovered the turtles bodies threshold.

Now to find out sunlight to supplement. I'm aware reptiles stop converting D3 when there is enough, but this will not effect the ratio. Using the Ca toD3 ratio, give your turtle 1g of calcium and expose it to 1 hour of sunlight. Measure Ca level in pee. If there is a calcium in it, increase exposure to 2 hours. If there isn't, lower sunlight exposure until there is. Then you'll find a new ratio. The ratio of Calcium to duration of sunlight. With the Ca to D3 ratio and Ca to sunlight ratio, you can figure out how much D3 is needed both with supplement or UVB lighting.

There are numerous variables and you really have to control for them. For example, activity level effects the results, since muscle contraction requires calcium,you would need to control for how much your tortoise is moving unless its pretty constant over time. The size of the tortoise must remain constant then since bigger tortoises have more muscle mass, so to do this experiment, you can't extend it over months of time. You may not be able to get an exact amount, but you can get a good average of the need they have. You also can't tell if the amount of calcium in veggies is the same per area of leaf. The only way to control that is to feed pure calcium and D3 pills. As you can see, there is no ethical way of doing this without keeping your tortoise in a box where ti cant move and feeding it pills all day. Even in human studies, they control your diet and the amount of activity each person does.

------------------------------------

As for the UVB studies, most dont say how much trials there were. If I remember right, the p-value determines its signifance. To put it in simple terms, the signifance pretty much determines that the results that you are getting did not occur by chance. Logically, the more trials there are, the less likely you'll see those results if it was luck that gave you the result the first few times. In science, to be significant, you p-value has to fall under 5%. 

From what I remember on Dr Maders results, it never indicated the amount of trials. The differences were so small, in the tenth of a percents, that it is hard to say they are even significant. For a difference that small, the experment would have to be replicated 100 to 1000s of times to show any significance.

The only thing you can conclude from those results is either UVB bulbs dont do jack, or all bulbs are equally effective.


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## pyxistort (Dec 22, 2009)

Could any one provide UVB Light Bulb usage informtion/study for tortoise? If there is no information available, why people still say you have to use UVB light bulb? 

Scott


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## -EJ (Dec 22, 2009)

I'm posting the link to the Google search. I have no desire to delve into it because I have a pretty good grasp of the topic...

http://www.google.com/search?hl=en&...=0CAYQBSgA&q=Dr.+William+Gehrmann+UVB&spell=1

Dr. Gehrmann has been doing and publishing the results of this studies long before the advent of the internet.



pyxistort said:


> Could any one provide UVB Light Bulb usage informtion/study for tortoise? If there is no information available, why people still say you have to use UVB light bulb?
> 
> Scott


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## pyxistort (Dec 22, 2009)

Haha... Thank you, EJ. I am not expecting you to answer this. 

This is the information to support that UVB light bulb is beneficial for tortoise, but it is not must have. When people suggest it is must have, they must be base on some hard evidence. But, I guess there is no such support.

Scott



-EJ said:


> I'm posting the link to the Google search. I have no desire to delve into it because I have a pretty good grasp of the topic...
> 
> http://www.google.com/search?hl=en&...=0CAYQBSgA&q=Dr.+William+Gehrmann+UVB&spell=1
> 
> Dr. Gehrmann has been doing and publishing the results of this studies long before the advent of the internet.


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## Madkins007 (Dec 22, 2009)

Here is a list on uvguide.co.uk of articles, some of which are by W H Gehrmann: http://uvguide.co.uk/references.htm


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## gummybearpoop (Jan 15, 2010)

Arizona has plenty of UVB outside!!! Whoot Whoot!


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## Tom (Jan 17, 2010)

Research and statistics are all well and good, but I trust my own experience and instincts a lot more. Even better than that is advice from someone who has had long term success with the species in question.

You want to know how to do something right? Ask someone whose been doing it right for a long time.


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