The people without sufficient iodine in their food probably have rather narrow diets. Subsistence farmers on the great plains? Protestant subsistence farmers not forced to eat fish sticks or tuna casserole on Friday? But everybody uses salt.
I use cheap sea salt because it tastes better. And I eat fish or other seafood quite often.
Other than the texture, which is similar to kosher salt, it’s just NaCl, just like table salt is.
Note that kosher salt has no difference in taste when added to soups, stews and the like. The difference in kosher salt is the* texture,* not the taste. Recipes for soups, etc that call for kosher or sea salt are being pretentious.
Now, “Grey” Sea salt, which is quite expensive, does have a different taste.
Yes, it’d have to be a very light broth or something.
Not noticeable.
Also grey salt contains a small amount of iodine normally, and is how many used to get their iodine.
Salt is the one food product that everyone on earth uses. Iodination of salt was David Letterman’s mother’s cause celebre, because she remembered people with goiters and other disabilities resulting from iodine deficiency.
“Iodine allergy” usually means that a person is allergic to iodinated contract media, which is quite common. Most people are not allergic to dietary iodine, although some people with thyroid issues have to watch their iodine intake carefully.
Also, the non-iodinated salt is used by people who use it for non-food purposes like crafts, cleaning, etc. The iodinated product can be cloudy or otherwise compromise the final product.
In present American society, however, most people get too much salt, largely by way of processed foods.
The only non-iodized salt I get is the large crystal Kosher salt, with no anti-caking agents. The larger crystals trigger a much stronger taste response; I can definitely tell the difference. Of course, that probably wouldn’t be the case in soups and such.
Also, iodine is a small simple ion, easy to add to sodium chloride. That is why iodine isn’t in milk, and vitamin D in salt.
I suspect we all eat enough processed foods made with iodized salts that we can use non-iodized in our own cooking if we like.
That’s true, but people who live in the high Andes or central Africa or Asia may not otherwise get sufficient iodine. It takes less than a penny of iodine to fortify a ton of food-grade salt.
Goiter and congenital hypothyroidism (formerly called cretinism) used to be very common in the Great Lakes region, which was why Mother Letterman did what she did. 
A while back, I saw a news report about this, and in this case they were reporting from the Andes. They were at a hospital that was most likely run by missionaries, and every pregnant woman who came to the clinic was given an injection of iodine in oil, to make it slow-release. This was sufficient to protect the baby.
I disagree. My tastes in food are by no means sophisticated but I like to use good ingredients. Sea salt has a noticeably different flavor than regular table salt iodized or not, even in baked goods. Technically all salt i of course “sea salt” but, the more commercially prepared stuff is very heavily processed, and the iodine is noticeable in things like popcorn. Now, the “boutique” stuff at 20 bucks a pound from the Himalaya is getting off the reservation. I’m still working off a huge bag of Morton’s pickling salt that is iodine free. Iodine can add a chemical odor or taste that some find objectionable. But sea salt is good stuff too. I really like it with eggs.
But that’s not soups. Everything you mentioned, the salt crystals stay crystals - they don’t dissolve into separate sodium and chloride (and iodine) ions.
huh? Salt is completely dissolved in baked goods, scrambled eggs, and countless other dishes.
Should add that I’m a little frugal too, or at least wouldn’t tolerate the extra cost if it wasn’t worth it. If forced, to use descriptive adjectives I’d say a sea salt adds depth to foods, that regular table salt doesn’t quite match. It’s not a deal breaker but again, it’s worth using. A couple pounds lasts a long time so it’s not going to break the bank.
That link is all about iodine deficiencies. Which used to be a big problem. I believe they chose salt as the delivery system for iodine for two reasons: 1. Everyone eats salt, and 2. You only need a very small amount of iodine, so it needed to be placed in something that is only eaten in small amounts.
You can overdose on iodine, but it’s practically impossible to do so from salt:
Unless it’s that "boutique "grey salt stuff, no it doesn’t. It’s NaCl, with a label. No significant difference in flavor, other than in your head.
On popcorn, you get a difference due to texture. same with steaks.
*To make sense of all these claims, we tasted two kinds of table salt (one iodized, one not), two brands of kosher salt, and five widely available sea salts. The price per pound of all the salts ranged from 36 cents to $36. Tests were divided into three categories: salt used at the table (we sprinkled each sample on roast beef), salt used in baking (we used a plain biscuit recipe), and salt dissolved in liquids (we tested each salt in spring water, chicken stock, and pasta cooking water).
Of the five tests run, we uncovered the most profound differences in our beef tenderloin test. Tasters loved the crunch of the large sea salt flakes or crystals when sprinkled over slices of roast tenderloin. Why did the sea salts win this test? Large crystals provided more pleasing sensory stimulation than fine table salt. In fact, tasters really objected to fine salts sprinkled on the beef, calling them “harsh” and “sharp.” Tasters did like kosher salt on meat, but not as much as sea salts, which have larger crystals.
…
In the biscuit tests, table salt was the winner, and most of the sea salts landed at the bottom of the ratings. The explanation here is simple. Small salt crystals are more evenly distributed in baked goods than large crystals, and tasters didn’t like getting a big hit of crunchy salt.
In the spring water, chicken stock, and pasta cooking water, tasters felt that all nine salts tasted pretty much the same. Why didn’t the fancy sea salts beat the pants off plain table salt in these tests? The main reason is dilution. Yes, sea salts sampled right from the box (or sprinkled on meat at the table) did taste better than table salt. And while crystal size did undoubtedly affect flavor perception in the tenderloin test, we suspect that our tasters were also responding favorably to trace minerals in these salts. But mineral content is so low in sea salt that any effect these minerals might have on flavor was lost when a teaspoon of salt was stirred into a big pot of chicken stock.
…
What, then, can we conclude from the results of these tests? For one, expensive sea salts are best saved for the table, where their delicate flavor and great crunch can be appreciated. Don’t waste $36-a-pound sea salt by sprinkling it into a simmering stew. If you like to keep coarse salt in a ramekin next to the stove, choose a kosher salt, which costs just pennies per pound. If you measure salt by the teaspoon when cooking, use table salt, which is also the best choice for baking.*
Yet Cretinism was first noted in the High Alps, at a time when it was neither popular nor profitable — no doubt in earlier ages people just accepted all forms of mental lagging, and indeed mental illness, as just folk being folk; or if they were pious, rolling their eyes and claiming it was God’s Will — of course the Alps are not that far from the sea, but backpacking rotting fish miles uphill never really caught on.
Being malnourished is common in many places far removed from starvation. It’s not difficult to miss out.
And I meet various nutcases who eschew salt completely, and denounce it, despite the medical evidence shifting back in salt’s favour the last decade, as ferociously as others of their gullible ilk denounce alcohol, or tobacco or whatever the current villain de jour may be.
Salt is not only the White Gold, essential to life and mental balance, but more needful than any gold ever could be.
Actually, it doesn’t.
Nah, it really does taste different. You should try it sometime and find out for yourself.
It should be pointed out too, sea salt is available in different grind levels, from fine all the way to extra coarse. That’s kind of a rookie mistake for those folks I’m thinkin’. I especially like sea salt in stews and soups, it really excels there. If they can’t taste the difference it’s not my problem, they aren’t feeding me anyway.
Perhaps “dissolve” is the wrong word, but, no, the sodium and chloride ions do not disperse evenly through out foods like eggs - even scrambled - and certainly not baked goods, not unless you dissolve the salt in water before adding it to flour. A large salt crystal gives stronger flavor; that’s how taste buds work.
I think you misspelled “uselessly pedantic”, when I bake things or make scrambled eggs the salt is indeed dissolved, there isn’t anything left. I’m not a big biscuit fan, but make a LOT of bread and pizza, the dough prep thoroughly mixes and dissolves up the salt. In fact the only kind I buy is extra coarse, but there is nothing left after several minutes through a Kitchen-Aid.
Anyway, in case the OP is still wondering about this, I buy non iodized salt to use in fabric dyeing. Iodine can mess with the color results. I generally use pickling salt because it dissolves faster, which is handy when you’re trying to mix several cups of salt in a few gallons of water. I would guess that there are some other nonfood-related recipes involving salt in which iodine is either unnecessary or unwelcome.