For some reason Iodine seems to highligh a deficieny or/and aggravate (bring to surface?) an underlying condition.
This is what I have observed over and over again at this forum during my 6 years here. One get pain in the back, the next get pain in joints, others get fatigue, hairloss, etc etc. This is usually a trancient phase, but it may persist if one lack the element needed to correct it. Some do well on low dosages of iodine, others need way more. Anyway some co-supplements are needed in most cases.