If you are only using one supplement for powdering your crickets it should be some sort of Calcium powder. Occasional dusted crickets with Calcium is a MUST, but a Multivitamin is COMPLETELY optional (and just like it is for people, it's redundant to use multivitamins if you already eat nutritious foods). You only need to powder crix with Calcium 1-2x per week, and non-dusted food should still make up more than half the diet. What's MOST important is what you feed your crickets before you feed them to your frogs.