Jurassi-cal may be an "ok" source for calcium. You will likely need a source for Ca/D3 also. Most of us use products like Miner-All (I) and Miner-All (O) or Rep-Cal w/D3 and Rep-Cal W/O D3. In addition, many of us use Herptivite for other vitamins. Finding a source for vitamin A is a whole other story . Do a Search of this site for more info on VItamin A vs. beta-carotene .
I may have asked before, but what part of So.Cal. are you located? I'm in Manhattan Beach.
Supplementing with calcium/D3, sunlight or no sunlight can end-up in an overdose situation. Think of dusting with Ca/D3 as "mainlining" it directly into your critter's system without the body's ability to self-regulate it. Naturally created D3, through exposure to sunlight and, more or less, artificial UVB light sources, is regulated by the body's own internal processes. It is essentially created in the levels needed to properly utilize the calcium present in the bloodstream.
So the thing to remember is if your critter will be exposed to unfiltered natural sunlight for many hours a day then it will only need calcium supplements and no added D3. If, for example, he only gets sunlight on the weekends then he may only require calcium with D3 a couple of times a month. No sunshine and only UVB from a typical fluorescent tube then maybe calcium with D3 once a week along with regularly scheduled calcium supplementation on top of that. I specifically didn't mention how often because it all depends on what insect, what gutload, the age of your chameleon, the health situation etc. There are many charts and postings out there with suggestions as to how often etc.