I was borderline a couple of years ago, but a subsequent test two months later said I was okay. The guidelines changed a couple of years ago re: what number is considered low thyroid. They changed it, an by so doing, put millions into the low thyroid camp. My mother had it and takes a drug for it. I'm going to have mine checked again. It's more common than people realize.
I read about it a couple of years ago and remembered info on b vitamins. This is someone's personal view:
http://thyroidstory.mivox.com/node/107