I recommend using a phos free calcium powder at all feedings lightly except for 4 a month (one day a week). On two of those days, 2 weeks apart, I dust with a phos free calcium/D3 powder lightly...and on the remaining 2 days 2 weeks apart, I dust lightly with a vitamin powder that contains a beta carotene prOformed source of vitamin A. If your chameleon shows signs of needing it, you can also give a preformed vitamin A once in a while...but be careful...it builds up in the system and can cause health issues.
Calcium with no phos or d3 during the week. Lately I've started adding a little bee pollen powder to the calcium.
Repashy Calcium Plus LoD on weekends, sometimes I skip a weekend.