For what its worth, my doctor who recommends and uses vitamin D said he wasnt concerned if my vitamin D went over 100. He might have mentioned there are no known toxicity cases of it, or something along these lines... basically I wasnt going to put myself in any acute danger if I went over 100.
Now if I went over 200... then maybe :D but once I got to 90's I cut my dose to 5k IU daily. I have yet to get follow up bloods for that, but I will in a few months probably.