Uvb and D3

[Herpvet]

Yep, I do too. Pretty much all of the multivitamin supplements around contain at least some D3 but I can't imagine the frogs getting enough to cause hypervitaminosis and the other vitamins are nice to have I definitely wouldn't rely on supplements to get adequate amounts of any vitamin let alone D3 though, much better to concentrate on a varied, well gut loaded diet and UVB and use supplements as a safety net. The problem in some circles is that a culture of feeding (usually one) easy to obtain feeder insect and throwing powder at it has developed. To me, that's a bit like giving a human a multivitamin pill and nothing but cheese sandwiches. You wouldn't die, but your health wouldn't exactly be optimum either.

Whilst I agree with much of what you say, I would take issue with your comment that "you can't imagine the frogs getting enough [vitamins] to cause hypervitaminosis". Again data is lacking in amphibians (one report is cited in Wright & Whitaker - but how many amphibs routinely undergo post-mortem exam?), but it is not uncommon to see older (usually male) reptiles with blood vessel calcification; hypervitaminosis D is a real possibility. And when you consider supplements are typically "1 pinch per kg of animal" or similar, the difference of a few particles to a dart frog, say, could be a huge overdose. Vitamin supplements are not risk-free by any means. I do use, and recommend, supplementation in many cases (and of course deficiency issues are FAR more common) but care is definitely needed.

Unfortunately as has been mentioned, ideally we need studies including serial radiographs/bone density assessments, and blood sampling if feasible, to evaluate our captive animals, and crucially compare them to wild specimens (the studies that have been done in herps tend to suggest that even our "clinically healthy" animals are often not comparable in bone density and/or blood vitamin D3 levels to wild animals). While certainly not decrying the efforts and skills of keepers who have reared many species/generations of apparently healthy animals, unless all animals are examined for evidence of pathology, particularly post-mortem, then there will always be doubt.