The truth is, iodine levels have fallen by approximately 50% in the United States over the last 30 years, according to the NHANES data. (National Health and Nutrition Examination Survey).  This drop was seen in all demographic categories.  The percentage of pregnant women with low iodine concentrations increased 690% over this time period.

Why? - 

Iodine was added to salt in the 1920's to help combat thyroid goiter. I was taught in medical school that there is enough iodine in salt to supply the body's need for iodine, however, I have been investigating this topic extensively and there are in fact no studies to back up these claims.

Also, iodine is primarily added to refined salt, which is a devitalized product that is exposed to toxic chemicals in order to give it a white color.  The ingestion of refined salt does in fact lead to many health problems.  Unrefined sea salt, on the other hand, is full of minerals and short on chemicals and should be the salt of choice, however it does not supply adequate iodine. 

There are many many reasons why the western world is in a state of iodine deficiency, too much for me to get into right now, but in a nutshell: Poor farming techniques have led to iodine deficient soil, radioactive iodine, used in many medical procedures, exacerbates iodine deficient states, Exposure to chemicals such as bromide, flouride and chloride all inhibit iodine binding in the body. FYI - diets high in baked goods lead to iodine deficient states, since bromine has replaced iodine in the baking industry.  I hope to offer a workshop on this topic in the future, but for now, I hope I can convince you suffering with thyroid issues that it is imperative to have your iodine levels checked with a iodine loading test.  Must be done by a doctor proficient in this area.  I am happy to make recommendations.