I use the zoo med repticalcium + d3 and the directions say to use it every week. So I use that plus the regular calcium every day.
The fact is bearded dragons, iguanas and chameleons all have very different requirements nutritionally, so a blanket statement like that on a supplement bottle is best ignored.
I have a few chameleons and this is the only one with the problem so I doubt I am doing anything wrong. I believe the animal has a problem.
She sure looks like she has a problem and since it's in the area of the kidneys, they could be the problem but I hope it is not.
A good vet, familiar with treating chams is needed to make a diagnosis.
It isn't really clear just how often you've been dusting with D3 but if it is daily, that far exceeds the amount any cham should have.
Extended overuse of calcium with D3 will damage internal organs.
The lack of a multivitamin generally causes deficiencies, so I hope you dust 2x a month with a multivitamin. Very few people have such superb gutloading which contains everything that's needed, which is why most of us use a multivitamin once or twice a month, depending on species, to prevent any deficiencies.
The dusting schedule zlew listed is one that the forum moderators recommend for non-montane chams ---whose supplements are typically half of that.
Hopefully, it turns out to be nothing serious.
Is she acting normal or are there changes in her appetite or demeanor that also point to a health issue?