More on the debate as to the requirements of humans for iodine; a paper I have just come across by Abraham whose later writing tends to be acerbic. He appears frustrated at the unwillingness of the wider medical establishment to engage with / consider the issue of iodine, and understandably so if he is right. Indeed the evidence increasingly seems to point to a greater need for iodine than is recognised in current dietary guidelines. Deficits will be exacerbated by the increasing impact of iodine blockers. The varied evidence of Japanese intake all points to intakes greater than 1mg a day and probably higher; the health of the Japanese would suggest that such intake levels are not inherently harmful and may confer significant health benefits.
I am aware that the UK advisory body is currently considering the issue of iodine intake.
It is interesting that the paper reports higher thyroid volumes in Ireland and Germany.
It is also interesting that Switzerland apparently adopted a doses of 3mg.
Some of the historical references are fascinating
Effect of daily ingestion of a tablet containing 5 mg iodine and 7.5 mg iodide as the potassium salt, for a period of 3 months, on the results of thyroid function tests and thyroid volume by ultrasonometry in ten euthyroid Caucasian women.
Guy E. Abraham M.D., Jorge D. Flechas M.D., and John C. Hakala R. Ph.
http://cypress.he.net/~bigmacnc/drflechas/IOD1.htm
"Considering the importance of this element for overall well-being, it is most amazing that no study so far has attempted to answer the very important question: What is the optimal amount of daily I intake that will result in the greatest levels of mental and physical well-being in the majority of a population with a minimum of negative effects?"