The iron issue was brought up by tom. I was simply replying to that. I then said "back to frogs" as I continued my post.

As for dusting, I believe this is a highly debated topic and we really do not have all of the questions answered. After looking through some of my posts, I believe a few of my points were unclear so I will restate what I am trying to say.

Supplements can be given in excess and lead to an overdose. Many vitamins and minerals have lethal levels.

Calcium should not be used too often (about twice a week is what many suggest). Although less dangerous for a chance of overdose, extra calcium that your frog can't use will just require more work for the frogs internal systems.

Overall, it is better to just gut-load. If done properly then the insects will carry with them all of the nutrition required by the frog for healthy growth and metabolism.