Re: [gecko]Walk about farms gecko dust

[Leann Christenson]

The amount of dietary D3 need not and likely should not change with the amount of UVB in my opinion (especially if ambient temperature ranges are similar).   The big problem isn't the dietary D3, its those stinkin' UV lights - so inconstant.  From day one when they are installed, the UV light produced no longer a reliable constant.  We have to take in consideration how old the bulb is, the space from the gecko to the bulb, how long the light is on each day...etc ("but I bought that UV light a year and a half ago, how come my gecko is getting sick now??").     Phelsuma appear to have as good a system for homeostasis as do other lizards and other vertebrates. They will absorb the dietary D3 they need. Lizards' digestive and absorptive physiology will change to extract the D3 they need from diet...   Yeah!  Someone gets my point and says it so well!!   That is why I rely on that good Phelsuma system that uses dietary D3 so efficiently.  Phelsuma, when provided the dietary D3 don't need UV lights.  And the good news, Phelsuma seem to do it much more efficiently than most other day dwelling reptiles.    UVB with or without a reasonable level of dietary D3 has never caused a cause of hypervitaminosis D. UV lights may seem not to cause D3 toxicity but they certainly are responsible for MBD when their UV strength dwindles.  When it comes to Phelsuma the toxic vitamin of concern is A.   Leann         ----- Original Message ----- From: [EMAIL PROTECTED] To: [EMAIL PROTECTED] Sent: Monday, February 09, 2004 2:51 PM Subject: Re: [gecko]Walk about farms gecko dust << However, what is not mentioned is how much vitamin D3 is needed by Phelsuma is directly related to the lights being used over the gecko's enclosure.  When a day gecko is kept under high level UV producing lights like Reptisun 5.0 or natural sunlight than a vitamin/calcium supplement low in D3 is idea.  >> I would disagree with this statement. The amount of dietary D3 need not and likely should not change with the amount of UVB in my opinion (especially if ambient temperature ranges are similar). Phelsuma appear to have as good a system for homeostasis as do other lizards and other vertebrates. They will absorb the dietary D3 they need. Lizards' digestive and absorptive physiology will change to extract the D3 they need from diet, just as (at least some lizard spp) lizards can change basking times to make up for dietary D3 deficits. When the system breaks down is when the dietary D3 is excessive, overwhelming the homeostatic system.  That level looks to be >30 or 50 IU/g total diet dry matter (dust plus prey) although it might be higher when calcium levels are <1% diet dry matter. Toxicity arises from bypassing the controls at the gut level (such as with intramuscular injections) or from providing toxic intakes by mouth and overwhelming the controls at gut level.  UVB with or without a reasonable level of dietary D3 has never caused a cause of hypervitaminosis D. regards, Sue Susan Donoghue, VMD, DACVN Owner, Nutrition Support Services, Inc. HerpNutrition at Walkabout Farm www.HerpNutrition.com