Hi Scott! I guess the first question would be is if you house your tegu(s) outside in direct sunlight or inside as many of us Michiganders do. :0) Even with UVB lighting, research has been leary as to identify the actual longevity of the bulbs. Ther eare many contradictory findings. Anyways, I have always used Rep-Cal brand, phosphorous-free with Vit. D3 (pink label) with great success! One thing is it easier to locate here in michigan, then add shipping costs of the Miner-all. When feeding the SDZ diet, rep-cal, along with herpevite by rep-cal (blue label) are the supplements i use and have had very good success with it, especially in reds with sdz due to the fruit content. (B&W's and even Blues) can get dirhea if they eat too much of the fruit-content in SDZ needed by reds in shedding.
Hope this helps!
Greg