Supplementation is still being debated, as there is not a one schedule fits all for chameleons. I've noticed that it can even differ between different animals of the same sex and species, I.E. one being more sensitive to a d3 supplement than another. Personally, I use plain calcium every feeding to every other feeding, with d3 once or twice a month tops depending on how much natural UVB exposure they get. A bi-monthly multi-vitamin is recommended as well, but this supplement is also an area of debate over the best way to provide vitamin A I believe.. Some theorize that the most effective way to supply it is by using a multi-vitamin with beta-carotene that is transformed into vit. A through some biological process. Currently, I am conducting an experiment with the Exo terra multi vitamin and reptivite to see if there is really a need for Beta-carotene or not.
Someone correct me if I have some incorrect information as this is just information that I have read, and when it comes to chameleons, it is a little difficult to determine the validity of some sources as chameleons are still a little bit of a mystery. Good luck with your Cham. BTW