Another thought to keep in mind. I learned this lesson the hard way with a veild.
If your using a supplement with D3, which is sounds like you are, than you want to stop all vitamin D3 supplementation before taking your cham outside. Not all calcium supplementation, but definately all D3 supplementation. I had a male veiled that was roughly 6 months old that I had been giving Miner-All I to about twice a week along with a vitamin supplement that I use that has no D3 in it. I took him outside for about a half hour and everything seemed great. He basked in the sun to whole time. This guy was the absolute picture of health. I was planning on using him as a future breeder. Then that night when I went up to his cage he was dead on the cage floor with what looked to be like foamy spit all around his mouth. Later I would find out from a vet that in all probability he died of a D3 toxicity. And veileds live on the edge of the desert in Yemen, so their D3 threshold is probably a bit higher than panthers. This is why sticky tounge farms makes an indoor formula and an outdoor formula. Same for Repcal. They make a calcium without D3 and a calcium with D3.
D3 is a fat soluble vitamin. Water soluble vitamins like B and E are easily passed through the system if any amount of excess has been given. Fat soluble vitamins like D and A on the other hand are a completely different story. With these vitamins, the animals store what they're given. If too much is given, it can become toxic enough to actually kill your cham.
Just some food for thought. I dont want anyone to run into the problem that I had. Just for the record. In the summer time, I completely discontinue all D3 supplementation for at least a couple weeks before I start taking my chams outside. But when you discontinue D3 supplementation, you definately want to make sure your cham gets outside for at least an hour or more a week just to make sure he's absorbing enough D3 through the sun.