Quote from their site:
Should I gutload my crickets with calcium?
We see a lot of products on the market that feature a "Calcium Gutload". It is our recommendation that you stay away from those products. A small amount of calcium in the cricket feed is appropriate.
A cricket has no internal skeleton. When you supercharge your cricket with calcium, their exoskeleton becomes brittle. Once that occurs, they cannot molt. If they are unable to molt, then they die - that simple. Also, a brittle cricket is more difficult for your herp to digest.
It is best to coat your cricket with a calcium dust every other feeding. Our Kricket Complete feeding package has the calcium dust and duster to cover all of your calcium needs.
http://www.premiumcrickets.com/cricket-care_p4.html