Iodine deficiency is one of the first places I'd look. From http://www.optimox.com/pics/Iodine/IOD-10/IOD_10.htm:
Iodine deficiency may cause the ovaries to develop cysts , nodules and scar tissue. At its worse this ovarian pathology is very similar to that of polycystic ovarian syndrome (PCOS). As of the writing of this article I have five PCOS patients. The patients have successfully been brought under control with the use of 50 mg of iodine per day. Control with these patients meaning cysts are gone, periods every 28 days and type 2 diabetes mellitus under control.
If you'd like to do an iodine test, simply PM me. I do the test that Optimox (the website above) recommends.
Note--putting oneself on 50mg of daily iodine without proper medical supervision is NOT a good idea.