Many areas of the world have a historical prevalence for thyroid issues due to iodine deficiency. One of those areas is the Great Lakes region which is rather heavily populated.
Often people in these regions are misled to believe that their vegetables are a source of iodine when in fact, because the land is iodine deficient, so are the plants grown in that area.
Iodine is often an ingredient in medications and is often used to sterilize milking equipment in dairy operations. Therefore care must still be taken because if a person (children in particular) is ingestion large amounts of dairy and/or cough/cold medicines, there is a risk of too much iodine if supplementation is pursued.
This bit of knowledge extends to people who are on a homemade bread diet, gluten free diet or dairy free diet as they may not be achieving the iodine levels required for proper thyroid function. I urge them to talk to a medical professional about iodine supplementation (even more so for those who are on a dairy free, low salt diet).
Those who may be on a homemade bread (of any kind), grain low, paleo diet or grain free diet as they are not receiving the same supplementation as general society (who eat store bought bread that is artificially supplemented with iodine). This issue is often overlooked by medical professionals and review often needs to be initiated by the patient/spokesperson for the person(s) at issue.
Dr. James Howenstine has written an article that suggests even people on 'regular' store-bought bread are now running the risk of being low in iodine, since some breads may include bromine instead of iodine. He states that bromine not only replaces iodine in the bread but inhibits iodine uptake by the thyroid gland (iodine that comes from other foods).
Iodine deficiency can contribute to Grave's Disease, adrenal fatigue, Raynaud's, goitre, cretinism (rare if salt is supplemented with iodine and used regularly in the diet), fatigue, weakness, depression or weight gain. Even signs as simple as physical and/or mental fatigue can be an indicator of iodine deficiency. Lead toxicity is another issue that is affected to iodine deficiency. It is iodine that aids the body in the purging of lead. Insufficient iodine and lead levels have a better possibility of building up. It has also been strongly associated with breast cancer.
As always, my interest in failure to grow makes this an extremely interesting realm of information and anyone dealing with ftt (failure to thrive) should address the possibilities with their health care provider.
I have noted subtle differences that seems to emerge slowly in our family dynamic with addition/removal of high iodine foods. Whether it's the iodine levels or something else is debateable. However, we seem to fare better with these foods and I have found myself, several times over the past few years realizing that if I overlook the addition of these foods within our diet, we just don't do as well... whatever the reason.
Nevertheless...
Sea vegetables, like seaweed (dulse is one kind) can help prevent a myriad of issues that develop due to iodine deficiency. Likewise, this type of food, because of it's high levels of iodine must be carefully monitored by people on thyroid medications.
Though it is commonly believed that iodine added to salt is sufficient, there are many medical professionals who debate this issue hotly and insist that supplemented salt is not anywhere near sufficient for the thyroid gland to work as effectively as it should.
It is often said that Asian diets are higher in iodine. However, this type of blanket statement is debatable. Generally speaking, I would consider it a 'rumour' and not base my dietary intake on how closely a person follows an 'Asian Diet'.
A high fish diet is also not an indicator of iodine levels since one would need the knowledge of where the fish came from, on which to base this supposition.
One suggestion to increase iodine levels would be to add it (in the form of dried dulse or kelp) to two of your basic recipes (spaghetti sauce or taco meat) that are enjoyed twice a week. Sea vegetables are often salty and may subsequently require a reduction of salt in these recipes.
Sardines are another source and could be used instead of salt or sea vegetables in such dishes. If bones are intact, mash it all up and it will add a good bit of calcium to your recipe also. Oily fish will have the added benefit of essential fatty acids. It is said that because sardines have such a short lifespan, they do not have the same issues regarding mercury. Anchovies would be another suggestion.
Recipes to add these ingredients would be pizza (to replace the salt in the dough or tomato sauce), spaghetti sauce, taco meat, rice casseroles, etc.
As always, be certain that you are not allergic to either seafood or iodine (said to be unrelated in some source articles though I'd imagine there are times when this claim would be debatable). Though some allergies are not common, it is always wise to be aware and take care. Consult your personal medical professional re: sensitivities to these foods.
Here is a link to more info. that I collected and posted at Neurotalk a couple of years ago:
http://neurotalk.psychcentral.com/showthread.php?t=1207&page=2
Sources:
http://www.vegansociety.com/html/food/nutrition/iodine.php
http://www.whfoods.com/genpage.php?tname=nutrient&dbid=69
http://www.springerlink.com/content/x71g7280270127p4/
http://query.nytimes.com/gst/fullpage.html?res=9A04E0DD1F38F932A35751C1A96E958260&sec=&spon=&pagewanted=1
http://query.nytimes.com/gst/fullpage.html?res=9A0DEEDB1F39F937A35755C0A960958260&sec=&spon=&pagewanted=all
http://www.whfoods.com/genpage.php?tname=foodspice&dbid=135#healthbenefits
http://www.newswithviews.com/Howenstine/james37.htm
http://www.allergy.org.au/aer/infobulletins/seafood_allergy.htm
http://www.naturalfoodpantry.com/news.htm
http://www.florahealth.com/flora/home/Canada/HealthInformation/Encyclopedias/Dulse.htm
)... some fun stuff for end-users.