Update UI from inside a loop

Hi i have this really slow for-loop which creates prefabs and materials using code. I would like to have a UI text field update and show the loop iteration, Unfortunately the for loop exits only once its finished and the UI text does not update in the UI field although I change its .text property in the for loop. I suspect that this is happening because the Update() function is not called, because of the blocking inside the loop. Is there a way to force update the UI from inside the for-loop, in order to have it show the loop iterations. Thanks Dimi