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
