While I was scrubbing the web for Iodine info, I found this interesting tid-bit.
"Iodine is vital to your hair growth. Sheep farmers long ago found that vegetation-lacking Iodine due to iodine-depleted soil would adversely affect the growth of wool in their sheep. Likewise, to avoid hair loss, you need iodine. Iodine is synthetically added to table salt , however in this form it is not assimilated well into your body and can therefore cause iodine overload.
An excess of iodine in the body can adversely affect the thyroid. The lack of iodine can cause hypothyroidism. In hypothyroidism, your cell metabolism slows down and body cells and hair cells don't receive the energy they need to function properly. When you lack iodine, you will lose more hair than normal and may even lose eyebrow hair."