Added D3 has been proven to cause impactions.

[VARNYARD]

Yes it is true, all though D3 has many side effects if overdosed; it has now been linked to impactions in studies that have been done. So if you are having impactions in your reptiles, you might need to change your supplement to one that is free of D3. As a side note, whole prey items (Mice, Rats, Chicks) and proper UV removes the need for any D3 additives.

 

[Azaleah]

Wow thats nuts! I feel like I have been lied to. Everyone always says the calcium with D3 is the best... I am definately going to stop using it and just use normal calcium.

 

[VARNYARD]

Wow thats nuts! I feel like I have been lied to. Everyone always says the calcium with D3 is the best... I am definately going to stop using it and just use normal calcium.

I agree, I have been using Herpavite with D3 in it, but I am changing to the new Rep-Cal with no D3 and no added phosphorus.

 

[VARNYARD]

Rep-Cal Calcium is Phosphorous Free and has No Vitamin D3

Calcium deficiency is a major dietary problem of captive reptiles and amphibians. Maintaining a proper calciumhosphorous (Ca) ratio in the diet of 1.5:1 is believed to be just as important nutritionally as an adequate Ca intake. The problem in most cases is an improper Ca ratio, not too little Ca.

Ca ratios of common cultured food items are shockingly poor:

Using a calcium supplement that also adds phosphorous makes no sense as an adequate Ca ratio can never be achieved. Bone meal contains phosphorous. Rep-Cal contains only 100% Natural phosphorous-free oyster shell Calcium Carbonate for its calcium source.

 

[Azaleah]

Yea I actually had that at home for my gravid female leopard geckos, but more commonly used the type WITH D3. Now I know better. Thanks for the info, Bobby!

 

[tupinambis]

Can you reference that finding?

 

[Nero]

Weird study for reps changes as much as human study on whats good and whats not good for you. So should I not use dusted crickets for my dragon and gecko anymore? Or is there a minimum uses on d3?

 

[VARNYARD]

Cholecalciferol or D3:

Chemically, the various forms of vitamin D are secosteroids; i.e., broken-open steroids.[5] The structural difference between vitamin D2 and vitamin D3 is in their side chains. The side chain of D2 contains a double bond between carbons 22 and 23, and a methyl group on carbon 24.

Vitamin D2 is derived from fungal and plant sources, and is not produced by the human body. Vitamin D3 is derived from animal sources and is made in the skin when 7-dehydrocholesterol reacts with UVB ultraviolet light at wavelengths between 270Ã?Æ?Ã?â??Ã?â??Ã?¢Ã?Æ?Ã?¢Ã?¢ââ??¬Ã?¡Ã?â??Ã?¬Ã?Æ?Ã?¢Ã?¢ââ?¬Å¡Ã?¬Ã?â?¦Ã¢â?¬Å?300 nm, with peak synthesis occurring between 295-297 nm.[6][7] These wavelengths are present in sunlight at sea level when the sun is more than 45Ã?Æ?Ã?â??Ã?¢ââ??¬Ã?¡Ã?Æ?ââ?¬Å¡Ã?â??Ã?° above the horizon, or when the UV index is greater than 3.[8] At this solar elevation, which occurs daily within the tropics, daily during the spring and summer seasons in temperate regions, and almost never within the arctic circles, adequate amounts of vitamin D3 can be made in the skin after only ten to fifteen minutes of sun exposure at least two times per week to the face, arms, hands, or back without sunscreen. With longer exposure to UVB rays, an equilibrium is achieved in the skin, and the vitamin simply degrades as fast as it is generated.[1]

In humans, D3 is as effective as D2 at increasing the levels of vitamin D hormone in circulation; [9] However, in some species, such as rats, vitamin D2 is more effective than D3.[10] Both vitamin D2 and D3 are used for human nutritional supplementation, and pharmaceutical forms include calcitriol (1alpha, 25-dihydroxycholecalciferol), doxercalciferol and calcipotriene.[11]

Biochemistry
Vitamin D is a prohormone, meaning that it has no hormone activity itself, but is converted to the active hormone 1,25-D through a tightly regulated synthesis mechanism. Production of vitamin D in nature always appears to require the presence of some UV light; even vitamin D in foodstuffs is ultimately derived from organisms, from mushrooms to animals, which are not able to synthesize it except through the action of sunlight at some point in the synthetic chain. For example, fish contain vitamin D only because they ultimately exist on calories from ocean algae which synthesize vitamin D in shallow waters from the action of solar UV.


Production in the skin

The epidermal strata of the skin. Production is greatest in the stratum basale (colored red in the illustration) and stratum spinosum (colored orange).The skin consists of two primary layers: the inner layer called the dermis, composed largely of connective tissue, and the outer thinner epidermis. The epidermis consists of five strata; from outer to inner they are: the stratum corneum, stratum lucidum, stratum granulosum, stratum spinosum, and stratum basale.

Vitamin D3 is produced photochemically in the skin from 7-dehydrocholesterol. The highest concentrations of 7-dehydrocholesterol are found in the epidermal layer of skin, specifically in the stratum basale and stratum spinosum.[6] The production of pre-vitamin D3 is therefore greatest in these two layers, whereas production in the other layers is reduced.

Synthesis in the skin involves UVB radiation which effectively penetrates only the epidermal layers of skin. While 7-Dehydrocholesterol absorbs UV light at wavelengths between 270Ã?Æ?Ã?â??Ã?â??Ã?¢Ã?Æ?Ã?¢Ã?¢ââ??¬Ã?¡Ã?â??Ã?¬Ã?Æ?Ã?¢Ã?¢ââ?¬Å¡Ã?¬Ã?â?¦Ã¢â?¬Å?300 nm, optimal synthesis occurs in a narrow band of UVB spectra between 295-300 nm. Peak isomerization is found at 297 nm. This narrow segment is sometimes referred to as D-UV.[12] The two most important factors that govern the generation of pre-vitamin D3 are the quantity (intensity) and quality (appropriate wavelength) of the UVB irradiation reaching the 7-dehydrocholesterol deep in the stratum basale and stratum spinosum.[6]

A critical determinant of vitamin D3 production in the skin is the presence and concentration of melanin. Melanin functions as a light filter in the skin, and therefore the concentration of melanin in the skin is related to the ability of UVB light to penetrate the epidermal strata and reach the 7-dehydrocholesterol-containing stratum basale and stratum spinosum. Under normal circumstances, ample quantities of 7-dehydrocholesterol (about 25-50 Ã?Æ?Ã?â??Ã?¢ââ??¬Ã?¡Ã?Æ?ââ?¬Å¡Ã?â??Ã?µg/cmÃ?Æ?Ã?â??Ã?¢ââ??¬Ã?¡Ã?Æ?ââ?¬Å¡Ã?â??Ã?² of skin) are available in the stratum spinosum and stratum basale of human skin to meet the body's vitamin D requirements,[6] and melanin content does not alter the amount of vitamin D that can be produced.[13] Thus, individuals with higher skin melanin content will simply require more time in sunlight to produce the same amount of vitamin D as individuals with lower melanin content. As noted below, the amount of time an individual requires to produce a given amount of Vitamin D may also depend upon the person's distance from the equator and on the season of the year.



Synthesis mechanism (form 3)
1. Vitamin D3 is synthesized from 7-dehydrocholesterol, a derivative of cholesterol, which is then photolyzed by ultraviolet light in 6-electron conrotatory electrocyclic reaction. The product is pre-vitamin D3.
2. Pre-vitamin D3 then spontaneously isomerizes to Vitamin D3 in a antarafacial hydride [1,7]Sigmatropic shift.
3. Whether it is made in the skin or ingested, vitamin D3 (cholecalciferol) is then hydroxylated in the liver to 25-hydroxycholecalciferol (25(OH)D3 or calcidiol) by the enzyme 25-hydroxylase produced by hepatocytes, and stored until it is needed.

25-hydroxycholecalciferol is further hydroxylated in the kidneys by the enzyme 1α-hydroxylase, into two dihydroxylated metabolites, the main biologically active hormone 1,25-dihydroxycholecalciferol (1,25(OH)2D3 or calcitriol) and 24R,25(OH)2D3. This conversion occurs in a tightly regulated fashion.

Calcitriol is represented below right (hydroxylated Carbon 1 is on the lower ring at right, hydroxylated Carbon 25 is at the upper right end).


Mechanism of action
Once vitamin D is produced in the skin or consumed in food, it is converted in the liver and kidney to form 1,25 dihydroxyvitamin D, (1,25(OH)2D) the physiologically active form of vitamin D (when "D" is used without a subscript it refers to either D2 or D3). Following this conversion, the hormonally active form of vitamin D is released into the circulation, and by binding to a carrier protein in the plasma, vitamin D binding protein (VDBP), it is transported to various target organs.[5]

The hormonally active form of vitamin D mediates its biological effects by binding to the vitamin D receptor (VDR), which is principally located in the nuclei of target cells.[5] The binding of calcitriol to the VDR allows the VDR to act as a transcription factor that modulates the gene expression of transport proteins (such as TRPV6 and calbindin), which are involved in calcium absorption in the intestine.

The Vitamin D receptor belongs to the nuclear receptor superfamily of steroid/thyroid hormone receptors, and VDR are expressed by cells in most organs, including the brain, heart, skin, gonads, prostate, and breast. VDR activation in the intestine, bone, kidney, and parathyroid gland cells leads to the maintenance of calcium and phosphorus levels in the blood (with the assistance of parathyroid hormone and calcitonin) and to the maintenance of bone content.[14]

The VDR is known to be involved in cell proliferation, differentiation. Vitamin D also affects the immune system, and VDR are expressed in several white blood cells including monocytes and activated T and B cells.[11]


Nutrition
Only fish is naturally rich in vitamin D, so much vitamin D intake in the industrialised world is from fortified products including milk, soy milk and breakfast cereals or supplements.[1]

A blood calcidiol (25-hydroxy-vitamin D) level is the accepted way to determine vitamin D nutritional status. The optimal level of serum 25-hydroxyvitamin D is 35Ã?Æ?Ã?â??Ã?â??Ã?¢Ã?Æ?Ã?¢Ã?¢ââ??¬Ã?¡Ã?â??Ã?¬Ã?Æ?Ã?¢Ã?¢ââ?¬Å¡Ã?¬Ã?â?¦Ã¢â?¬Å?55 ng/mL; with some debate among medical scientists for the slightly higher value.

The U.S. Dietary Reference Intake for adequate intake (AI) of vitamin D for infants, children and men and women aged 19Ã?Æ?Ã?â??Ã?â??Ã?¢Ã?Æ?Ã?¢Ã?¢ââ??¬Ã?¡Ã?â??Ã?¬Ã?Æ?Ã?¢Ã?¢ââ?¬Å¡Ã?¬Ã?â?¦Ã¢â?¬Å?50 is 5 micrograms/day (200 IU/day).[15] Adequate intake increases to 10 micrograms/day (400 IU/day) for men and women aged 51Ã?Æ?Ã?â??Ã?â??Ã?¢Ã?Æ?Ã?¢Ã?¢ââ??¬Ã?¡Ã?â??Ã?¬Ã?Æ?Ã?¢Ã?¢ââ?¬Å¡Ã?¬Ã?â?¦Ã¢â?¬Å?70 and up to 15 micrograms/day (600 IU/day) past the age of 70. These dose rates will be too low during winter months above 30Ã?Æ?Ã?â??Ã?¢ââ??¬Ã?¡Ã?Æ?ââ?¬Å¡Ã?â??Ã?° latitude. In the absence of sun exposure, 1000 IU of cholecalciferol is required daily for children. 4000 IU of vitamin D may be required for adults absent summer UVB. [1]


Milk and cereal grains are often fortified with vitamin D.In light of its apparent health benefits, The Canadian Cancer Society recommends that non-white adults take 1,000 IU daily year-round and whites take that amount in fall and winter. The Canadian Pediatric Society recommends 2,000 IU daily for pregnant and breastfeeding women.[16]


In food
Season, geographic latitude, time of day, cloud cover, smog, and sunscreen affect UV ray exposure and vitamin D synthesis in the skin, and it is important for individuals with limited sun exposure to include good sources of vitamin D in their diet.

In some countries, foods such as milk, yogurt, margarine, oil spreads, breakfast cereal, pastries, and bread are fortified with vitamin D2 and/or vitamin D3, to minimize the risk of vitamin D deficiency.[17] In the United States and Canada, for example, fortified milk typically provides 100 IU per glass, or one quarter of the estimated adequate intake for adults over the age of 50.[1]


Fatty fish, such as salmon, are natural sources of vitamin D.Fortified foods represent the major dietary sources of vitamin D, as very few foods naturally contain significant amounts of vitamin D.

Natural sources of vitamin D include:[1]

Fish liver oils, such as cod liver oil, 1 Tbs. (15 mL) provides 1,360 IU
Fatty fish species, such as:
Herring, 3 oz provides 1383 IU
Catfish, 3 oz provides 425 IU
Salmon, cooked, 3.5 oz provides 360 IU
Mackerel, cooked, 3.5 oz, 345 IU
Sardines, canned in oil, drained, 1.75 oz, 250 IU

Overdose symptoms may include headache, weakness, drowsiness, dry mouth, nausea, vomiting, constipation, muscle or bone pain, metallic taste in the mouth, weight loss, itchy skin, changes in heart rate, loss of interest in sex, confusion, unusual thoughts or behavior, feeling unusually hot, severe pain in your upper stomach spreading to your back, or fainting.

Oral calcium supplements (such as Neo-Calglucon and Nutrobal) are useful for long term calcium therapy but the benefit of vitamin D3 therapy must be weighed against the dangers of iatrogenic hypercalcemia and soft tissue mineralization. The use of full spectrum light sources (e.g., Zoo Med Reptisun 5.0 or Iguana light) or better still sunlight is safer. Monitor Ca ratios on a regular basis

There appears at this point to be more research the use of oral and injectible D3 and the use of UVB in iguanas, the world's largest herbivorous lizard, than there has been with tortoises, most species of whom are also completely herbivorous. A.C. Highfield did do some studies, however, using UVB-producing lights. Both groups were fed identical diets. One group got only a little UV lighting, a D3 supplement, and calcium supplement. The other group got more UV and only a calcium supplement. Both groups did fine - until the UV output of the tube used in the second group began to degrade. Once it was replaced, and a little D3 added to their diet, the softening shell hardened again. Unfortunately, since D3 was added as well as the bulb replaced, it is unknown from this study whether the UV light alone would have made a difference. From what I have seen and experience myself, however, I believe that it would have.

References:

Alberts, A. (1994) Ultraviolet light and lizards: More than meets the eye. The Vivarium, 5(4):24-25.

Alderton, David. (1992) Turtles and Tortoises of the World. Facts on File Publ., New York.

Allen, M.E., Oftedal, O.T., Baer, D.J., and Werner, D.I. (1989) Nutritional studies with the green iguana. In, Proceedings of the Eighth Dr. Scholl Conference on Nutrition of Captive Wild Animals, pp. 73-81. Lincoln Zoological Gardens, Chicago, IL.

Ball, J.C. (1995) A Comparison of the UV-B Irradiance of Low-Intensity, Full-Spectrum Lamps With Natural Sunlight. Bulletin of the Chicago Herpetological Society, 30(4):69-71.

Bernard, J.S., OT Oftendal, et al. (1991.) The response of vitamin D deficient green iguanas (Iguana iguana) to artificial ultraviolet light. Proc Am Vet 1991:147-150.

Bernard, J.S., Oftedal O.T., Ullrey, D.E. Idiosyncrasies of Vitamin D Metabolism in the Green Iguana (Iguana iguana). Proceedings, Comparative Nutrition Society Symposium, pp. 11-14

_____ (1996) Metabolic Bone Disease, pp. 385-392. In, Reptile Medicine and Surgery. D. M. Mader, Ed. WB Saunders Company, Philadelphia PA.

Boyer, Donal M. and Thomas H. Boyer. (1994) Tortoise care. Bulletin of Assn of Reptile and Amphibian Veterinarians, 4(1):16-28.

Donoghue, S. and Langenberg, J. (1996) Nutrition, pp. 148-174. In, Reptile Medicine and Surgery. D. M. Mader, DVM (Ed.) WB Saunders Company, Philadelphia PA.

Gehrmann, W.H. (1992) No UV-B from Tungsten Filament Incandescent Lamps. Bulletin of the ARAV 2(2):5

_____ (1996) Lighting. In, Reptile Medicine and Surgery. Douglas Mader, ed. WB Saunders Company, Philadelphia PA.

Heatwole, H.F. and J. Taylor. (1987) Ecology of Reptiles. Surrey Beatty & Sons Pty Limited, Chipping Norton, Australia.

Highfield, A. C. (1996) Practical Encyclopedia of Keeping and Breeding Tortoises and Freshwater Turtles. Carapace Press, London.

Innis, Charles. (1994). Considerations in formulating captive tortoise diets. Bulletin of ARAV, 4(1)8-11.

Kreger, M.D. (1993) The psychological well-being of reptiles. Humane Innovations and Alternatives, pp. 519-523.

Mautino, Michele and Douglas Page. (1993) Biology and medicine of turtles and tortoises. VCNA: Small Animal Practice. Vol 23, No 6, pp 1251-1269.

McKeown, S. (1996) General Husbandry and Management, PP 9-19. In, Reptile Medicine and Surgery. D. M. Mader, Ed. WB Saunders Company, Philadelphia PA.

Warwick, C. (1990) Reptilian ethology in captivity: Observations of some problems and an evaluation of their Ã?Æ?Ã?â??Ã?â? Ã¢â?¬â?¢Ã?Æ?ââ?¬Å¡Ã?â??Ã?¦tiology. Applied Animal Behaviour Science, 26, pp. 1-13.

_____ (1990) Important ethological and other considerations of the study and maintenance of reptiles in captivity. Applied Animal Behaviour Science, 27, pp. 363-366.

Zimmerman, L.C. and Tracy, C.R. (1989) Interactions between the environment and ectothermy and herbivory in reptiles. Physiological Zoology, 62(2):374.

New research:
UV-lamps for terrariums: Their spectral characteristics and efficiency in promoting vitamin D3 synthesis by UVB irradiation

 

[VARNYARD]

The findings by reptile veterinarians, reptile nutritionists, and biologists are resultings are contrary to the claims made by the manufacturers of the vitamin products.

Also the side effects of an overdose of Cholecalciferol or D3 can be the same signs seen in the lack of proper D3 intake. It seems no one knows how much of this stuff is enough, or how much is too much. But one thing for sure is it can be deadly to your reptile. I can not say about animals that do not bask, but for the ones that do, proper UV is a must, and much safer than products with D3 added.

 

[tupinambis]

For the edification of people who may have troubles reading that bit above, there is NOTHING in the article that "proves D3 causes impaction". There is a warning that OVERDOSE may be related to constipation, which is not the same as impaction.

It does need to be put out that as vitamin D AND A are fat soluble, then it is quite possible and likely that oversupplementation will lead to harmful effects. But this is NOT the same as saying D3 will cause impaction. In the absence of good UVB and a well balanced diet, vitamin D3 is a good thing. Where keepers tend to go wrong is in the age old thinking "if a little is good, a lot must be better", and this is where problems arise.

However, it can also be said that too much calcium is also detrimental to your tegu's health, as is too much oxygen. Without carbon dioxide your tegu will die. If you don't understand the biological relevance behind these statements, you are likely to leap to the erroneous conclusion that you shouldn't give any calcium laden foods, should deplete the air your tegu breathes of oxygen, and instead give it CO2. These strategies would obviously kill your animal. But they don't change the fact that oversupplementation of calcium can lead to tissue calcification, impaction and calculi formation; too high of an O2 content leads to the formation of oxygen radicals that cause tissue damage and often leads to cancer; without proper levels of CO2 in your tegu's blood stream, the pH of the body fluids will change, it's cardioregulatory functions will shut down your tegu's breathing...you can see where this is going.

 

[Harveysherps]

With grown Tegus I can see where that would be true. But young ones that are growing. I find it hard to believe it will hurt them. Adults I can see that. But not babies and juvies. I can't say I can completely agree with that.

 

[VARNYARD]

Well tupinambis how much causes an OVERDOSE? How much is enough and how much is too much? If veterinarians, reptile nutritionists, and biologists say that these claims by these manufacturers are false, then maybe you can shed some light on it.

I have also never seen or heard of a tegu becoming impacted due to UV lighting, that said, D3 is not a safe choice.

And constipation is not the same as an impaction?

Impaction refers to the accumulation of dry, hardened feces in the rectum or colon. The patient with fecal impaction may present with circulatory, cardiac, or respiratory symptoms rather than with gastrointestinal symptoms.[2] If the fecal impaction is not recognized, the signs and symptoms may progress and result in death.

In contrast to constipation or impaction, an intestinal obstruction is a partial or complete occlusion of the bowel lumen by a process other than fecal impaction. Intestinal obstructions can be classified by three means: the type of obstruction, the obstructing mechanism, and the part of the bowel involved.

So yes, constipation is slow bowel movement; impaction is the next step, no movement or blockage.

Double-talking, right Colin?

 

[PuffDragon]

I don't know much on the topic but my herp vet said "you really really have to try and overdose on D3." Feeding 1-2 times a week won't do any harm. I use Dr. Joseph Filigno at Blackwood Animal Hospital, he can be found on HerpVetConnection.com

I am still trying to learn more on the subject before I form my own opinion however.

 

[tupinambis]

Well tupinambis how much causes an OVERDOSE? How much is enough and how much is too much? If veterinarians, reptile nutritionists, and biologists say that these claims by these manufacturers are false, then maybe you can shed some light on it.

Admittedly, what is an overdose is not clearly defined. What is an overdose in one animal may not be an overdose in another. Most clearly defined "overdoses" are exagerations designed to guarantee an outcome (usually death, but there are exceptions). However, lets apply your logic to feeding. We all know that overfeeding can lead to obesity, obesity unchecked will lead to premature death. By your argument, then, all feeding should be ceased immediately in order to prevent obesity. Clearly, this is not the advice you would suggest against obesity, is it? The fact of the matter is, vitamin D3 is a necessity, without it your animals WILL die. This doesn't mean going out and drowning your tegu in vitamin D3. As PuffDragon's vet has pointed out, one would have to be grossly neglegent in their supplementation in order to get vit D3 toxicity. You, on the other hand, are proposing the other end of the grossly neglegent spectrum in promoting its complete removal from use. In animals that are kept outside and given a well balanced diet, yes, vit D3 supplementation is not necessary at all. But for those animals being kept indoors, perhaps being fed a diet wherein the nutrient balance is not being attended to, telling someone to absolutely stop Vit D3 supplementation is very short sighted.

I have also never seen or heard of a tegu becoming impacted due to UV lighting, that said, D3 is not a safe choice.

But you have heard of a clearly documented case where a tegu was impacted by vit D3 supplementation? Please, point me in the direction of this article, I'd very much like to be properly informed on this matter.
However, I HAVE heard of cases where (like stated before) someone used the ole' "if a little bit is good, a lot must be better" cliche and caused damage to their lizard (admittedly not a tegu) through too much exposure to artificial, high intensity UV. Again, from your logic, beings as we don't know what an overdose of UV would be, wouldn't your argument be to completely do away with artificial UV all together? Oh, wait, that would be contradictory....

And constipation is not the same as an impaction?

No, constipation is not the same as impaction. Yes, it certainly can lead to impaction. Constipation can also lead to cloacal prolapse or egg retention. Does that mean constipation = impaction = cloacal prolapse = egg retention = herniation = etc. etc. etc.?

However, I'm having a hard time finding the exact source of your claim. I've looked through most of those references that your source supplied, and so far I have not come across any mention at all "proving" that Vit.D3 leads to impaction (or even a simple correlation for that matter). Most of them are talking about either Vit.D3 photoactivation or how supplementation is actually a GOOD thing. Which one is it that "proves" Vit.D3 causes impaction? Your "overdose" quote doesn't even mention D3, I'm supposing the original source did somewhere, but without it's context that "overdose" could be of any number of substances and is unclear.

There is no question at all in my mind, though, that yes overdosing Vit. D3 is a danger. Just as overdosing Vit.A is a danger. As I stated, they are fat soluble, meaning they can accumulate in fatty tissues of the animal and sufficient concentrations of them can build up to toxic levels. Completely eliminating it from a balanced diet is a greater danger. Impaction is primarily a case of poor husbandry in general, rarely has it been attributed to a single "smoking gun". Trust me, I frequently warn people not to overdo the Vit.D3 supplementation as well, but insisting that all supplementation of it should be stopped when the animals may not have proper UVB exposure or a good diet is just as negligent as overdosing the animal is.

 

[Harveysherps]

I have to say I would have to follow along with tupinambis and Puffy.
I have raised veiled chameleons to breeding size and then bred them. Using only T Rex chameleon dust. Keeping the phosphorus levels and calcium right has more to do with things than anything. I also used the same stuff on my Tegus when I had them. I never did use UV lighting. Savanah monitors were done the same way. and I never had a problem with them. Natures mist reptile spray is also a very good product. I would much rather suppliment the D3 than I have buy $40 and $50 bulbs. I will say this. If Calcium and phosphorus levels are kept right d3 isn't needed as much in Adult reptiles.

 

[VARNYARD]

Musings on D3 and UV...

Melissa Kaplan:
Every time I pick up a reptile magazine and look at the ads, or read posts on the Internet and electronic mailing lists, there seems to be some new product hitting the market making questionable, if not downright ridiculous or dangerous, claims.

The most recent group of products is particularly insidious. Spray-on-food vitamins, "solar" and "nocturnal" D3 drops, and very high output ultraviolet fluorescents are among the ones that concern me. (It should be noted that the same maker of these drops, being marketed as the ideal replacement for exposure to sunlight and UVB wavelengths, recently bragged to an iguana owner that their secret ingredient in their frozen Iguana Flower frozen "food" product is Welch's Grape Jelly. And they want to be taken seriously...)

Although there have recently been more studies than ever before done on reptile physiology, nutrition, and response to ultraviolet and vitamins, they still don't hold a candle to what has been done in the pet mammal area. What is particularly worrisome is those independent studies, completed by reptile veterinarians, reptile nutritionists, and biologists, that are resulting in findings contrary to the claims made by the manufacturers of the vitamin and lighting products.

Scams
For example, a popular reptile multivitamin, Nekton-Rep, was found in independent study (Donoghue and Langenberg, in Mader) to not contain four of the minerals listed on the "guaranteed analysis" label. One of those four minerals was (are you sitting down?) calcium! Susan Donoghue, a reptile vet/nutrition researcher, analyzed several reptile, dog, and general animal vitamins, and Centrum, a human multivitamin. She found all the reptile vitamins to be lacking in many minerals and trace elements. She recommends the use of a mammal or general pet multivitamin instead, or Centrum, a vitamin that has all trace elements, vitamins and minerals represented. In addition, she believes, based on empirical evidence gained through her own reptile practice and formal feeding studies, and the practices of other reptile vets, that no vitamin, reptile or otherwise, contains enough calcium for reptiles, especially for herbivorous reptiles.

One thing neither she nor any other researcher, private or pet product manufacturer, has done, however, is to determine the exact amount of each vitamin, mineral and trace element that is required each day to maintain, in conjunction with proper environment and diet, optimum health, for each species, or even generalized to a family or class. So, the claims of vitamin product manufactures whose packaging and ads state they provide exactly the amount the reptiles need are meaningless. The Four Paws representative I spoke to did nothing to convince me that this product was worthwhile; when I voiced my concerns with it, she huffed up and snidely replied "Well! People will buy anything that has a picture of their animal on it, whether it is any good for them or not."

The spray-on-food vitamins, at least, are not as harmful as the spray-on-animal vitamins. Reptile skin is designed to keep body fluids inside the reptile's body. This is one of the key differences between reptiles and amphibians. Amphibians have highly permeable skin that not only ties them to life in water or highly humid places, but also puts them at risk for injury, illness or death from so many substances. Rather than being stopped by the barrier of the skin, substances permeate through the amphibian skin cells, reaching the interior of the body. When reptiles evolved from amphibians some 250 million years ago, their impermeable skins meant they could adapt to life on land and away from water and high humidity. So, spraying an oily substance laced with vitamins is not going to do a thing to supplement their diet! Neither will spray-on moisturizers do anything for them - but, like the spray-on-reptile vitamins, they do enormously well lining the pet store's and product manufacturer's pockets.

Spray-on-food vitamins at least will get into the digestive tract. But are you giving them enough with each spray? As noted reptile vet Douglas Mader stated in an article a couple of years ago, anyone who claims to know the exact amount a reptile needs is lying. You are paying a lot of money for a plastic spray bottle, water, flavoring, and a little bit of vitamin. A better value for your money would be a good dry multivitamin product that you mix in with the reptile's food. (Centrum, and even human calcium carbonate tablets may be crushed to a powder and the powder added to the food.)

Vitamin D3
My article on Metabolic Bone Disease goes into the natural development of D3 in the body as a result of the previtamin D formed through exposure of the skin to ultraviolet B wavelengths, so I won't repeat it here. If you are unfamiliar with the process, or the numerous disorders clustered under the MBD umbrella term, please read that article.

D3 is formed naturally in the body through exposure to UVB wavelengths (290-320 namometer, or nm). These wavelengths are produced by the sun, but are filtered out by regular glass and plastic; even fine-mesh screen can filter out significant amounts. (The windows in our house block out the UV wavelengths - otherwise all fabrics within range of the window would fade out within just a few years. Glass used in constructing commercial aquariums/terrariums is also made from plain window glass.) Thus an animal needs to be exposed to direct sunlight. It doesn't take much for an organism to get the amount of UV needed to metabolize adequate amounts of D3 when (again, this bears repeating), the environment and diet are right. Human needs are satisfied by 45 minutes exposure to the sun a week. Reptile veterinarian and researcher Dr. Alison Alberts states that 30 minutes exposure to the sun a day is sufficient for green iguanas.

Carnivorous and omnivorous animals get D3 not only by their body manufacturing it through exposure to sunlight (even nocturnal snakes come out at dusk to bask a bit), but through eating healthy prey. Prey that is not healthy, prey that is fed a marginal diet or one lacking in proper nutrition, or is composed of old or sick animals, will result in malnutrition, including adversely impacting the predator's ability to properly metabolize and process the nutrients its digestive system extracted from the prey.

Plants, however, do not contain D3, cholecalciferol. Plants contain D2, ergocalciferol. Ergocalciferol has been found to be much less efficient in calcium metabolism than cholecalciferol. Herbivorous reptiles maintained on plant diets who are not given adequate amounts of UVB were found to develop MBD. Since no one knows how much D3 an herbivorous reptile needs, it can be a dangerous proposition to rely on supplementing D3 through use of oral vitamins. How much is enough? How much is too much? Unfortunately, more is not better. Too much D3 causes the same thing as not enough D3 - metabolic bone disease. How then can we assure that our herbivores and omnivores are getting adequate D3, but not too much?

The UVB Connection
As discussed above, UVB interacts with the skin to form previtamin D. This is then converted in the body, through the function of several organs, into D3. Thus herbivores are able to manufacture their own D3.

We herbivorous reptile keepers have a little problem in captivity. Many of our reptiles come from hundreds or thousands of miles away. Central American iguanas and tortoises kept in Scotland or Korea, for example, do not live in an area that gets the same amount of natural UVB that they would get living in their native habitat. James Ball's article on lighting contains a chart of the amount of UVB that hits the earth at a variety of latitudes and longitudes, with the amount hitting the equator at noon given for comparison. What Ball and other researchers have acknowledged, however, is that no one has measured exactly how much UVB the species who live in these areas actually get every day or even in aggregate over a period of time. It is one thing to say that "X amount of UVB hits the equator at noon." It is quite another, however, to say that, ergo, "every equatorial reptile needs to get X amount of UVB every day."

First off, it isn't noon all day long at the equator. Just as it does where we live, the sun rises in the east and sets in the west. During the sun's passage (well, okay, the earth's revolution around the sun!), the sun's light (the infrared, visible, and ultraviolet wavelengths) passes through the earth's atmosphere at an oblique angle, both as it rises towards midday and as it starts to set in mid-afternoon. This naturally filters out much of the intensity, the quantity, of the infrared (which produce heat) and ultraviolet wavelengths, with visible light growing and diminishing in the early morning and late afternoon accordingly.

UVB-Producing Fluorescent Lights
One of the big arguments against using low UVB-output fluorescents such as Duro-Test's Vita-Lite (True-lite is the name under which it is sold in the ECM) is that it doesn't produce the same amount of UVB as produced at the equator at noon. Well, sunlight doesn't produce the same amount of UVB at any other time of day, nor at any non-equatorial place, as it does at noon! The question, I believe is incorrect. Instead of asking "Does this UVB-producing fluorescent produce the same amount of UVB as produced by the sun at the equator at noon?", what we should be asking is "Does this light, in conjunction with my paying attention to the temperatures, photoperiod, stress levels and diet of my reptiles, prevent the onset of MBD?" For my, in my experience keeping a number of lizards and chelonians, the answer to the latter question is "Yes, it does."

A wild reptile, unless it has an anatomical/physiological abnormality or injury that prevents normal functioning of organs and systems, doesn't overdose on UVB in the wild. A study of captive iguanas, however, at the National Zoo, found that when they were kept under experimental very high output (VHO) UVB fluorescents, they developed a condition that, the researchers said, would, in mammals, be considered vitamin D toxicity - too much D. What concerns me greatly is the recent appearance on the market of UVB fluorescents, Reptile-D lights, which claim to produce 8% UVB (though physicists would argue with the method by which the 8% was derived). Observant readers of ads or packaging will have noted that the verbiage on the packaging and ads states "not intended for human use." Why? Because it has been determined that anything over 5% is dangerous to humans - eye disorders and skin cancer being the main concerns. As we have found with so many things, more is not necessarily better. If a low-output UVB producing light such as the 3% light made by Zoo Med, or the even lower output Vita-Lite, produce enough UV when used properly (no farther than 18 inches from the reptile, replaced every 6-12 months), why risk overexposure? (It is interesting to note that the makers of the Reptile-D 8% light have recently come out with a 3% light, despite their heavy marketing the over the past year that claimed their lights were so much better for our reptiles than all the other UVB producing lights. Why, I wonder? Perhaps because they realized that consumers out there were beginning to be worried about the "not for human use" warnings and so not buying their lights...so they were not getting the market share away from Zoo Med and Durotest they had hoped? Coming out with a competing 3% light certainly helps solve that little problem...)

There appears at this point to be more research the use of oral and injectible D3 and the use of UVB in iguanas, the world's largest herbivorous lizard, than there has been with tortoises, most species of whom are also completely herbivorous. A.C. Highfield did do some studies, however, using UVB-producing lights. Both groups were fed identical diets. One group got only a little UV lighting, a D3 supplement, and calcium supplement. The other group got more UV and only a calcium supplement. Both groups did fine - until the UV output of the tube used in the second group began to degrade. Once it was replaced, and a little D3 added to their diet, the softening shell hardened again. Unfortunately, since D3 was added as well as the bulb replaced, it is unknown from this study whether the UV light alone would have made a difference. From what I have seen and experience myself, however, I believe that it would have.

Personal Experience with UVB
I got a 9 month old captive bred and hatched Vietnamese leaf turtle (Geomyda spengleri) from the breeder. I set him up in an enclosure complete with a 15" Vita-Lite installed into an under-cabinet fluorescent fixture set on top of the screen top of the enclosure (the light itself was less than 12 inches above the turtle). His diet consisted of redworms (rinsed, blotted and dredged in a calcium supplement that contained D3), and snails gut-loaded on high calcium greens. After 3 months, I noticed that his shell was softening. I had the housing set up and was feeding him exactly as did the breeder, yet clearly he was getting calcium deficient. While I sat looking at him one day, it suddenly hit me: when I installed the Vita-Lite into the fixture, I then put the the plastic diffuser that came with the fixture back over the tube. Installed in a kitchen, this diffuser would reduce the glare of the light, providing an easy-on-the-human-eye diffused light. This same diffuser, however, also blocked the UVB wavelengths. With insufficient UVB, the turtle was unable to manufacture enough D3 (and was not getting enough from his supplemented prey to make up the difference) to metabolize enough calcium. Thus, calcium was not being replaced into his shell and, presumably, his bones.

I removed the plastic diffuser from the fixture, and put the fixture back on the enclosure, where it sits at the same 12 inches above the turtle. I did not increase his calcium supplement, nor did I add any more D3, nor did I increase the length of time every day that his Vita-Lite is on. Within 2 weeks, there was a noticeable difference in his shell; within another week, his shell was firm again and there have been no further incidents of softening. I also make sure to replace the bulb every 12 months.

What astounds me in the above incident is not that the diffuser blocked the UVB - I know that it does that. The astounding part is not only did I manage to forget that little fact, but that it had happened to me before!

A couple of years ago, I bought some compact Vita-Lites to try. Like non-UVB producing compact fluorescents, these plug into a ballast which in turn is designed to screw into an incandescent light fixture. I got them to try them to see if they would be a suitable replacement for the long Vita-Lite tubes. Three of us were using them for iguanas. In each case, MBD developed. In each case, we were using the plastic diffusers that came with the compact lights. I found, however, that removing the diffuser didn't correct the MBD for the large iguanas. Without changing the diet, the vitamin supplementation, nor the amount of time each day exposed to the light (which was within 6 inches of the iguanas), I corrected the problem by exposing the iguanas instead to a regular, straight Vita-Lite tube. Thus, not only is it direct access to the ultraviolet wavelengths that is necessary, it is also how much of the body is exposed. A compact UVB producing fluorescent just doesn't produce enough UVB over wide enough area to be effective for 3-4+ feet of lizard. Given that the skin of a chelonian is presented only at the most extreme ends, I wouldn't use a compact UVB-producing fluorescent for them either, unless they were very small hatchlings, out of fear that not enough of their skin would be exposed to the wavelengths.

I regularly encounter people who seem to be raising healthy lizards and chelonians without benefit of UVB or sunlight. But the fact is that metabolic bone disease is still one of the the most common illnesses/disorders found by reptile veterinarians. To me, and many of the reptile veterinarians who write about chelonian and lizard care in captivity, it just makes sense to provide both UVB, either sun or artificial produced UVB, and a properly constructed and supplemented diet.

The Other Ultraviolet
Most discussions of ultraviolet wavelengths address UVB. There is, however, another segment in the ultraviolet spectrum that is also critically important. UVA (320-400 NM) is the range in which reptiles, and many other animals, can see. What looks like a faintly red-orange anole dewlap to us is a bright, fiery red beacon to another anole. That pretty blue tongue in a blue-tongue skink's mouth is bright fluorescent pink to another blue-tongue skink. Reptiles also have more color receptors in their eyes and so are able to better discriminate colors than are humans.

While all senses play an important role to reptiles, vision is probably one of the most versatile. The wavelengths they are able to perceive play roles in color perception which in turn affects appetite. Reds are redder, greens greener, yellows yellower. Transformed, then, is the rather bland, largely monotonous pile of greens, vegetables and fruits. For a reluctant feeder, the presence or absence of UVA may mean the difference between feeding, weight gain and growth, or malnutrition (due to chronic starvation) and stunted development.

Natural behaviors, too, may be stimulated by UVA. From thermoregulatory triggers that tell the reptile when to bask, feed, and find a sleeping spot for the night, to cues triggering onset of hormonal changes that kick off the breeding season, to tracking and identifying conspecifics in the environment (much like way a dog can learn about an interloper from smelling urine, many reptiles leave - and can read - UV sensitive trails or markers in their environment). Denying reptiles UVA would be like going through life with only one eye. You could certainly see and function, but you would be missing much of the depth and complexity of your environment. To a reptile, that depth and complexity makes up for the lack of spoken communication and, in many cases, very limited stereo (binocular) vision. To deny them UVA is to reduce their ability to effectively interact with their environment and with other animals in their environment, which in turn leads to chronic low levels of stress.

Stress, Malnutrition and Vitamin Disorders
Too many people who understand that a lousy diet, stressed-out lifestyle, long days, and too little sleep take a toll on the body that popping vitamin supplements won't correct, nonetheless act as if they believe that providing an inadequate environment and marginal diet can be remedied by loading their reptile with vitamins. Just as it won't work in humans, it won't work in reptiles. This, combined with the fact that we just don't know what exactly each species' vitamin and mineral requirements are on a daily basis, means that we need to act both conservatively to ensure we don't overdose them, but to also ensure that they are given the best opportunity to let natural systems go to work to keep them in balance.

Many of the reptiles in captivity are wild-caught. Even captive bred animals are subject to stress, some more than others. It is increasingly being found in many species, including reptiles, that chronic low levels of stress may have long lasting impacts, especially on the immune system. Chronic immune stress results in decreased immune response, thus impairing the organism's ability to fight off infection. As is being found with many human disorders, stress also leads to the reduction or increase of many different hormones, including natural cancer and infection fighters. As we are seeing more reptiles being kept for longer periods of time in captivity, we are starting to see more diseases and disorders that may be related to long term chronic stress.

No matter how hard we try, when we keep a nonnative species, we are at best only approximating its environment. Try as we may to replicate the temperatures, photoperiod, and topography, we can rarely replicate diet or even the nutritional make-up of their diets. The plants that herbivorous reptiles eat in the wild just aren't found in the produce section of our markets. As for nonnative species, not only are complete plant inventories often nonexistent on a species-by-species basis, we have no hope of ever obtaining those plants and growing them ourselves. So, at best, we must try to provide a proper diet made up of foods known to be safe, for which we can do some rough computations of their protein, fiber, and vitamin content, and for which we make ourselves aware of phytocompounds that may adversely affect our herbivores' and, to a lesser extent, omnivores' health - plants that adversely affect calcium metabolism and thyroid function are the two most commonly encountered. (See Highfield's Dietary Considerations article, and the feeding and foods section of my Iguana Care, Feeding and Socialization document for discussions of these plants.) For our omnivores and carnivores, we must be sure to feed health prey. "You are what you eat" is true when it comes to our reptiles. As with being unable to feed our herbivores native plant species, we are also generally unable to feed our predators natural prey - prey that their species would feed on in the wild. We don't know what minute but cumulative effects on them that this has. We do know that feeding old, unhealthy, oversized or heavily chitinous prey does pose health risks. So just as we must try to construct a proper plant based diet for our herbivores, we must strive to provide a healthy variety of healthy vertebrates and invertebrates to our omnivores and carnivores.

Conclusion
What we can do--what we must do--is to make sure we give our reptiles the best possible chance to be as healthy as possible. Doing so will mean that their internal systems will function properly, or as properly as it can in what is still an alien environment. The best way to do this is not only by meeting their environmental (physical and psychosocial) needs, but by providing additional tools, in the form of both multivitamin (which contain D3) and calcium supplements - and UVB wavelengths, either through regular exposure to the sun or 10-12 hours a day exposure to UVB-producing fluorescents (placed no further than 18" from the animal and replaced at least annually).

 

[VARNYARD]

Once again I ask the question, how much is enough and how much is too much, does anyone have the dose per weight for tegus?

We know it can kill, that is a proven fact, and it is just a real big question as to how much. I don't want to hear opinions as to the right amount; I want to see the facts by studies that it is safe. As for a vet, does he have any studies or the research showing it is fine to feed twice a week? Anything in his medical journals showing the proper amount for tegus?

I say proper diet and lighting are a must, anything less is just an unproven substitute.

 

[Harveysherps]

I can't do it for Tegus because the research hasn't been done. But Leopard geckos and such have been studied. The original maker of the T/ Rex formula was a genius . He sold his product to the big boys and lost out big time. But he had it done for the smaller types of reptiles. No one has taken the time to do this for the Big lizards . You know as well as anyone info on Tegus is limited. It is up to pioneers like yourself and others to test and proves points like this for the Tegus sake like Sandfire did for the Bearded Dragon and T /Rex. The only way to know what you can do is find out. So why not try to raise them without UV safely and effectively. The UV bulbs are way over priced. It works with chameleons and they have a low tolerance for vitamin A. But For several years and generations . I never once had any bone problems or anything. I used no UV lighting. Only the T/Rex powder on the feeders. I never fed them vegatable matter either. I feel you make a good point . But I think other good points have been made also. I respect your opinion on matters. But each keeper should use any means they can to provide what an animal needs. D3 is added to all kinds of stuff if you just look at it. Does it need to be taken out of Dog food , cat food and things such as that too.

 

[VARNYARD]

I can't do it for Tegus because the research hasn't been done. But Leopard geckos and such have been studied. The original maker of the T/ Rex formula was a genius . He sold his product to the big boys and lost out big time. But he had it done for the smaller types of reptiles. No one has taken the time to do this for the Big lizards . You know as well as anyone info on Tegus is limited. It is up to pioneers like yourself and others to test and proves points like this for the Tegus sake like Sandfire did for the Bearded Dragon and T /Rex. The only way to know what you can do is find out. So why not try to raise them without UV safely and effectively. The UV bulbs are way over priced. It works with chameleons and they have a low tolerance for vitamin A. But For several years and generations . I never once had any bone problems or anything. I used no UV lighting. Only the T/Rex powder on the feeders. I never fed them vegatable matter either. I feel you make a good point . But I think other good points have been made also. I respect your opinion on matters. But each keeper should use any means they can to provide what an animal needs. D3 is added to all kinds of stuff if you just look at it. Does it need to be taken out of Dog food , cat food and things such as that too.

I see your point Wes, but what about wild geckos? They do not bask, so how do they get this needed D3, If it is needed?

As I have said before, manufacturers of the vitamin products are out to market the products, does this mean what they say is fact? Do they know the safe amounts? One claims to feed it every day, is that safe?

What is the safest way to keep tegus? IMO, it is not taking risks with unproven products. Just my honest opinion. :igu

 

[VARNYARD]

A veterinarian, Dr. Keith Benson, said regarding Vitamin D3 or Solar drops:

"What I find interesting is that the dose is given irrespective of the size of the animal. Surely this will result in some overdosing and under dosing. D3 is considered (and this is based on very little, if any, data) safe at about 100 IU/kg/week in reptiles. The material in the bottle claims to have 1,500 IU per ml, and one drop averages about 1/20 of an ml. That would be like giving 750 IU - theoretically enough to treat 7.5 kilograms of reptile. Now, I realize that the dose might be higher than the one above, or lower - no one knows, even the folks that make this product Consider how concentrated this material is, then consider the damage that overdosing vitamin D can do (renal disease, soft tissue mineralization etc.) and I would say that until more data regarding the metabolism of this material in reptiles is know I would choose not to use it."

Vitamin D3 is a fat soluble vitamin. It is made naturally in the skin of most animals and it helps the animal use and digest the calcium in it's diet properly. An animal getting a well balanced diet, and UVB light or direct sunlight should not need vitamin D3 supplements in it's diet. It will be make enough of this important vitamin on it's own. If it is getting vitamin D3 supplements or too much vitamin D3 supplementation the D3, being fat soluble, can build up to toxic levels in the animals system.

Mader says: "Hypervitaminosis D produces soft tissue calcification. Vitamin D intoxication has followed ingestion of rodenticides containing cholecalciferol. Clinical signs in mammals are depression, anorexia, polyuria/polydipsia (frequent urination/excessive thirst), and weight loss. Treatment regimens for reptiles have not been tested by controlled clinical trials; currently, treatment should follow guidelines for other species, which often include glucocorticoids and calcitonin. "

You can have chronic renal failure in your animals by using these supplements, it is the progressive loss of kidney function and the damage cannot be undone. However, this is just one side effect, the build up, and overdosing can lead to many health problems, as stated before. Vitamin D over dosage will cause an excess amount of calcium to be absorbed, resulting in calcium deposits within soft tissues, including the heart. This can also build up over time according to the experts doing what little studies that are being done. This may occur secondary to over supplementation or following ingestion of rodentacides containing cholecalciferol.

Care should be taken not to over-supplement food with multi-vitamin products, as it is possible to overdose on certain vitamins, such as D3. Every reptile has its own requirements, and it is not wise to makes statements about nutrition to cover every one of them. Just be aware that it is possible to over supplement your reptile, and every reptile has its own requirements. Choosing to supplement your reptile's diet should not be taken lightly. This should be discussed with a good reptile veterinarian.

No one knows how much or how little is the correct amount; it is a chance I am not willing to take. I will spend the extra money for proper lighting before taking these chances.