i.nlm.nih.gov/pubmed/9768638">Iodine deficiency is common and increasing in prevalence, given the widespread avoidance of iodized salt. So what happens when you become iodine deficient? Here's a partial list:
--Weight loss is stalled or you gain weight despite your efforts. --Heart disease risk is escalated --Total and LDL cholesterol and triglyceride values increase --Risk of fibrocystic breast disease and possibly breast cancer increase (breast tissue concentrates iodine) --Gingivitis and poor oral health increase (salivary glands concentrate iodine)
(Naturopathic doctor Lyn Patrick, ND, has written a very nice summary available here.)
So how do you ensure that you obtain sufficient iodine every day? You could, of course, eat something from the ocean every day, such as coastal populations such as the Japanese do. Or you could take an inexpensive iodine supplement. You can get iodine in a multivitamin, multimineral, or iodine drops, tablets, or capsules.
What is the dose? Here's where we get very iffy. We know that the Recommended Daily Allowance (RDA), the intake to not have a goiter, is 150 mcg per day for adults (220 mcg for pregnant females, 290 mcg for lactating females). Most supplements therefore contain this quantity.
But what if our question is what is the quantity of iodine required for ideal thyroid function and overall health? Ah, that's where the data are sketchy. We know, for instance, that the Japanese obtain somewhere between 3,500 and 13,000 mcg per day (varying widely due to different habits and locations). Are they healthier than us? Yes, quite a bit healthier, though there may be other effects to account for this, such as a culture of less sweet foods and more salty, less wheat consumption, etc. There are advocates in the U.S., such as Dr. David Brownstein in Michigan, who argues that some people benefit by taking doses in the 30,000 to 50,000 mcg per day range (monitored with urinary iodine levels).
As is often the case with nutrients, we lack data to help us decide where the truly ideal level of intake lies. So I have been using and advocating intakes of 500 to 1000 mcg per day from iodine capsules, tablets, or drops. A very easy way to get this dose of iodine is in the form of kelp tablets, i.e., dried seaweed, essentially mimicking the natural means of intake that also provides iodine in all its varied forms (iodide, sodium iodate, potassium iodide, potassium iodate, iodinated proteins, etc.) This has worked out well with no ill effects.
The only concern with iodine is in people with Hashimoto's thyroiditis or (rarely) an overactive thyroid nodule. Anyone with these conditions should only undertake iodine replacement carefully and under supervision (monitoring thyroid hormone levels).
Iodine is inexpensive, safe, and essential to health and weight management. If it were a drug, it would enjoy repeated expensive marketing and a price tag around $150 per month. But it is an essential nutrient that enjoys none of the attention-getting advantages of drugs, and therefore is unlikely to be mentioned by your doctor, yet carries great advantage for helping to maintain overall health.