The biggest debate comes down to the fact that D3 is a fat soluble vitamin. This means (in humans) too much is hazordos for livers and other vital organs. How much is to much is debateable, and how toxic D3 is to Leos is another very grey area. I personaly prefer not to risk it and choose to use pure calcium in the dish for my Leo to get when ever it needs some. And dust the crickets with calcium with D3. It is said that they eat thier substrate in an attempt to raise thier calcium level thus providing a dish with calcium should prevent inpaction, and keep them in overall better health.

Thats the info, the choice is up to you on what you decide.