Most of us grew up believing the same thing: "I get enough iodine from my salt." It's the kind of assumption many of us never stop to question — one less thing to worry about, one box already checked in our health routine.
Here's the problem: it's a myth, and an outdated one. The idea that the salt in your shaker gives you enough iodine simply isn't accurate — and because iodine is one of the raw materials your thyroid and hormones can't function without, this is a detail worth getting right. So let's break it down, because it matters far more to your health than almost anyone tells you.
💡 Myth Buster
The myth: "I use salt, so I'm already getting plenty of iodine."
The truth: Much of the salt you eat isn't iodized at all — and the iodized kind supplies only one of the two forms of iodine your body uses. Relying on it can leave you low in iodine without knowing it.
First problem: much of your salt isn't iodized
Salt iodization was a genuine public-health success. Introduced in the 1920s, it corrected the widespread iodine deficiency that caused goiter. But it was never universal. Kosher salt, most sea salt, and Himalayan pink salt are typically not iodized. Neither is the large amount of salt in processed and restaurant food, which is where most people get the majority of their sodium.
Major brands sell both versions. Morton's blue-canister table salt is iodized, but its kosher, sea salt, and plain varieties are not — so "I use Morton" tells you nothing unless you've checked the label. Many people who assume they're getting iodine are using salt that contains none.
Second problem: iodized salt supplies only one form of iodine
Iodized salt provides iodide. Iodide is a usable form — the thyroid absorbs it directly through the NIS pump — but supplying a usable form is not the same as supplying enough of it (more on the amount below). And iodide is only one of the two forms of iodine the body needs.
The body also requires molecular iodine, which iodized salt does not contain. The two forms are taken up by different tissues: the thyroid uses iodide, while molecular iodine is the form used by estrogen-sensitive tissues — the breast, ovaries, and uterus all take up iodine, much of it in the molecular form. [1][2] At best, iodized salt supplies part of what the thyroid needs, and none of what the tissues beyond it require.
Third problem: it was only ever meant to prevent goiter
This is the key point. Salt was iodized to do one job — prevent goiter, the thyroid enlargement caused by severe iodine deficiency. It succeeded. But "enough to prevent goiter" and "enough for whole-body sufficiency" are very different amounts.
The iodide added to salt is keyed to the RDA — the minimum set to prevent deficiency disease. In our research and experience, that minimum falls well short of whole-body iodine sufficiency: the level that supplies not only the thyroid but the breast, ovarian, and other tissues that also depend on iodine. The RDA was designed to prevent deficiency disease, not to achieve whole-body sufficiency.
Fourth problem: most of it is gone before it reaches your plate
Even that small amount is unstable. Iodine is volatile and is lost with exposure to heat, light, moisture, and time, which is why manufacturers add stabilizers such as dextrose. The losses are well documented. Stored in an open container in humid conditions, iodized salt can lose about half its iodine within a single month, and studies have measured losses approaching 100% over several months of storage. [3] Cooking removes more — heating destroys roughly 15% to 60% of the iodine that remains. [4]
In practice, iodized salt is processed, shipped, stored in warehouses and on shelves, kept open in a humid kitchen for months, and then heated during cooking. By the time it is consumed, little iodine may remain, and there is no way to measure how much. As an iodine source, it is both minimal and unreliable.
Where your iodine should come from
First, where it should not come from: seaweed, kelp, and sea moss, despite being promoted as iodine "superfoods." Seaweed bioaccumulates contaminants from the water it grows in — it is used to help remediate polluted waterways — so it concentrates heavy metals and other contaminants along with iodine. There is no reliably clean seaweed source, and its iodine content is highly variable. It is not a source we recommend.
Foods like eggs and dairy contain trace amounts of iodine, but not consistently enough to rely on, and food will not reliably supply both forms of iodine.
This is why we made Thiodine. Its iodide is potassium iodide — the same usable form found in iodized salt — but the source, the dose, and the formula are different. Thiodine's iodine is deep-earth sourced from 100-million-year-old mineral deposits in the United States, laid down long before modern industrial pollution, so it is free of the contaminants found in sea-based sources. And it is a dual formula, supplying both molecular iodine and iodide at a meaningful dose — enough to reach the thyroid and the estrogen-sensitive tissues beyond it, not the token amount found in salt.
Isn't salt bad for me?
If your next question is whether we should all be eating less salt, the answer is more complicated than the standard advice suggests.
💡 Myth Buster
The myth: "I already eat too much salt. I should be cutting back."
The truth: The claim that nearly everyone consumes dangerously high sodium is not well supported. A growing body of research indicates that, for most healthy people, sodium's link to high blood pressure has been overstated, and that sugar and refined carbohydrates are more strongly associated with hypertension and metabolic disease. [5] Because processed food is the main source of both, the primary contributor is the processed food itself, not sodium. (If you have high blood pressure or a heart or kidney condition, your sodium needs are individual — follow your doctor's guidance.)
The body also regulates sodium tightly. In healthy people, the kidneys retain sodium when intake is low and excrete the excess when intake is high, directed by hormones such as aldosterone from the adrenal glands. Salt cravings can reflect this regulation, particularly when adrenal demand is high — which is common when thyroid function is low.
The goal is not to avoid salt, but to choose a clean source of it.
Not all salt is the same
The difference between salts is not the sodium chloride itself — it is the processing and what remains alongside it. Refined table salt is heavily processed and recrystallized, stripped of its trace minerals, then combined with additives such as anti-caking agents and dextrose. Many sea salts, at the other extreme, now contain contaminants including microplastics and heavy metals. A good salt is clean on both counts: free of additives and free of contaminants, while retaining its natural trace minerals.
This matters in an article about iodine because salt and iodine are physiologically linked. The NIS pump that transports iodine into cells is sodium-dependent. The adrenal glands require sodium and chloride. And adequate sodium and chloride support the clearance of the toxic halogens, such as bromide, that compete with iodine.
This is why we formulated Halodetox as a deep-earth-sourced, high-purity salt powder — free of additives and contaminants, but retaining its natural trace minerals. It is a clean source of the sodium and chloride the body requires.
The Bottom Line
This is the Thyroid Deficit in miniature: the body requires both iodine and clean salt, and the everyday sources most people rely on either fail to deliver them or introduce contaminants. Both gaps are straightforward to correct.
Ready to fix your Thyroid Deficit? Get started with HypoHero.
References
- Stoddard FR, et al. Iodine Alters Gene Expression in the MCF7 Breast Cancer Cell Line: Evidence for an Anti-Estrogen Effect of Iodine. International Journal of Medical Sciences, 2008. https://pmc.ncbi.nlm.nih.gov/articles/PMC2452979/
- Acute iodine deficiency induces a transient VEGF-dependent microvascular response in mammary glands. American Journal of Physiology–Cell Physiology, 2017. https://journals.physiology.org/doi/full/10.1152/ajpcell.00095.2017
- Diosady LL, et al. Stability of iodine in iodized salt used for correction of iodine-deficiency disorders. Food and Nutrition Bulletin, 1997. https://journals.sagepub.com/doi/pdf/10.1177/156482659701800409
- Wang GY, et al. Effects of storage and cooking on the iodine content in iodized salt and study on monitoring iodine content in iodized salt. Biomedical and Environmental Sciences, 1999. https://pubmed.ncbi.nlm.nih.gov/10442215/
- DiNicolantonio JJ, Lucan SC. The wrong white crystals: not salt but sugar as aetiological in hypertension and cardiometabolic disease. Open Heart (BMJ), 2014. https://pmc.ncbi.nlm.nih.gov/articles/PMC4336865/