Dr Del is correct with MBD.

There is more than one way to skin a cat, but short and simple. CGD is the safest thing to feed and you should never be told there is another,better, way to do it (or in my opinion, but I'm no expert.) These little geckos are from Caledonia and their staple of diet is nectar. CGD is the only way to provide the nutrients they need without many reverse side effects. I feed mine crickets maybe once a month. I have 2 adults and I'll toss in 7 to 10 crickets and there are some left a few days later.

Sense we are talking about food, adult male crested geckos are said to eat the babies. If you're breeding it's something to look out for.

If you look at the question on Iherp for an office pet there is a CGD you buy in bulk and comes in several different flavors. I'm not sure on price, but if you wanna keep several it's worth looking into. I'm about to do it now. I go threw a 5 dollar bottle of the little stuff in a month or so.