Excess intake can cause either hyper or hypo-thyroidism symptoms. Hypothyroidism seems to be much more likely in most of the literature. Here are a few articles that cover the process. One of the sites I read did mention menstration changes as a side effect, but the likelyhood was extremely low for short duration exposure. Good luck... damn students and their questions.
http://www.ehponline.org/members/200...cker-full.html
http://www.nlm.nih.gov/medlineplus/d...nt-iodine.html