Well its starting to get pretty warm here in Tucson, AZ. Im planning on letting my cham outside for an hour or two every day to get that much desired sun How will I need to change my supplementation if he is spending about an hour or two in the sun everyday?
When mine are getting pretty regular natural sunshine time I cut out the D3 completely from their supplement routine. Essentially I just stick to plain calcium, perhaps a multivitamin as well occasionally if it does not contain D3.
Just 20 minutes in natural sunshine produces enough vitamin D in the blood to be detectable 2 weeks later, so in my opinion there aren't any "gaps to fill," as there might be under a waning UVB bulb, for example. It packs a much greater punch.