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In addition to the advice hear keep in mind that lack of calcium and too much protein can be a problem for captive box turtles.

Box turtles will prefer protein over vegetables, but this not necessarily good. Their diet should be balanced. Many owners will keep feeding the box turtle a high protein diet (canned food, worms, etc.), because the box turtle appears to enjoy this. This is similar to providing a human child an unlimited supply of ice cream and pizza; the child will eat nothing else. Typically in the wild, protein food is naturally limited, because the box turtle must make an effort to find and catch it.
Healthy vegetables that provide high calcium and other nutrition are dandelions and turnip greens, both are fairly common. In addition to this other good fruits and vegetable are cactus fruit and figs. A mixture of other fruits is fine, too, but fruit should not be provided in high amounts either. The bulk of the diet should be green vegetables, and the other foods can be mixed in to get the box turtle to eat.

Finally a good box turtle multi vitamin should be added to the mix along with the proper UV lighting.
Since the last exchange I have put the box turtle back in the woods near where he came from. He had stopped eating in the terrarium.