"The History of Iodine Part 3 - Thyroid Fixation and Medical Iodophobia" by Guy Abraham...
As a public measure to control goiter, iodization of table salt was implemented successfully in the US between 1917 and 1924. That is, iodization of table salt was successful in decreasing markedly the incidence of simple goiter in the supplemented population. Keep in mind that the amount of bioavailable Iodine (0.05 mg/day) needed to prevent cretinism, endemic goiter, and hypothyroidism is 60 times less than the amount of Iodide (9 mg/day) used by Marine (2,3) in the original studies. Thyroidologists assumed that, with iodization of table salt , Iodine deficiency became a thing of the past. That was the beginning of thyroid fixation.
Prior to the iodization program, the public was relying on iodine preparations from apothecaries for their iodine needs. The recommended daily amount of iodine was 0.1-0.3 ml Lugol containing 12.5-37.5 mg elemental iodine. (4) This is exactly the amount of iodine needed for whole body sufficiency, based on a recently reported iodine/iodide loading test by the author. (4) Some propaganda was used following iodization of salt to discourage the public from using the iodine preparations, such as Lugol solution, and to rely instead on iodized salt for their iodine needs. In 1926, physician C.L. Hartsock, from Cleveland, Ohio, (5) wrote: "Iodized salt is now being very much more extensively used by the public than other forms of iodine, such as sodium iodide, iodostarine and compound solution of iodine (Lugol's solution), probably because of the propaganda to insure its use ..."
Iodized salt was unfortunately used as substitute for the previously recommended forms of iodine/iodide. The bioavailable Iodide from iodized salt is only 10% of the estimated 0.75 mg Iodide in iodized salt consumed per day. (6) That amount, 0.075 mg of bioavailable iodide, represents less than 1% of the amount of iodide used in Marine's study (2,3) (i.e., 9 mg) and also less than 1% of the recommended daily intake of iodine from Lugol solution. Implementation of iodization of salt was associated with an increased incidence of autoimmune thyroiditis. (4)