The Kammers are a great and unbelievably amazing source of information!A BIG problem with calyptratus is overfeeding - and I'm talking of babies, not adults. When they are in their first 2 months, their growth rate is set. And despite what many believe (including many breeders), their growth rate WILL change depending on food supply. Unlike other chameleons (every other kind I've heard of), they do not have two growth rates: Normal and slow (slow growth from not enough food). Veileds have a very variable fgrowth rate.
IF they are fed a little, they grow slow, and coudl be stunted. If they are fed more, they grow "normally'. If fed a lot, they grow very fast. If fed CONSTANTLY, as much as they can eat, every moment of their lives, they can and will grow so fast, their risk of MBD is increased exponentially. In fact, in many of these cases, it's aboslutly inevitable. I have had babies come in from other breeders that developed FATAL mbd within 2 months of arrival, despite UVB lighting, sunlight, and some supplemental D3.
The Kammers have told me that they have witnessed babies(not theirs, of course) grown in full, unfiltered, natural sunlight develop MBD, despite a good, balanced diet.
I have NEVER heard of other chameleons have this problem, only veileds.
At 5-6 months of age, this is less of an issue. Still, you don't want to have a fat chameleon.