I supplement with phosphorous-free calcium at most feedings. Insects have a poor calcium to phosphorous ratio, so this helps make up for it.
I dust the insects lightly with a vitamin/mineral powder twice a month making sure that the one I use has a beta carotene source of vitamin A. Beta carotene sources of vitamin A cannot build up in the system but preformed ones can.
Because my chameleons don't usually get any direct sunlight but only get UVB light (that doesn't pass through glass or plastic), I dust lightly with a calcium/D3 powder twice a month. D3 that comes from supplements can build up in the system so caution is necessary not to overdo it.
I also gutload all my insects appropriately.
Providing the proper temperature is important to digestion and thus to absorption of nutrients too.
Calcium, phosphorous, vitaminsD3 and A all need to be in balance for your chameleon to have good bone health.
Thanks for the replies. I bought Rep-Cal Calcium with Vitamin D3 and Rep-Cal Herptivite Multivitamin from what I have been reading these are to of the best supplement. For gut-loading I have been using Fluker's Calcium Fortified Cricket Quencher. Or would you reccommend a different type of gut-loader.