What Does Iodine Mean for Hashimoto’s?

Iodine is one of those subjects where you can quickly find conflicting information when you have Hashimoto’s.

One person says you should avoid iodine completely.

Someone else says you need extra iodine.

And if you simply want to know what makes sense for you, that does not make things any clearer.

So what does iodine actually mean for your thyroid if you have Hashimoto’s?

Why does your thyroid need iodine?

Iodine is an important building block for thyroid hormones.

Your thyroid uses iodine to produce hormones including T4 and T3. Without enough iodine, your body cannot produce these hormones normally.

That does not mean that more iodine is automatically better.

Your thyroid needs a certain amount. Taking extra iodine without a specific reason can actually be undesirable.

Why is iodine such a complicated subject with Hashimoto’s?

With Hashimoto’s, the immune system attacks the thyroid.

Over time, this can cause the thyroid to function less effectively.

Iodine is not the cause of Hashimoto’s, and avoiding iodine does not cure the autoimmune disease.

At the same time, a very high iodine intake can affect thyroid function. In people who are sensitive, large amounts of iodine may contribute to thyroid dysfunction.

That is why getting enough iodine is not the same as getting as much iodine as possible.

Do you need less iodine if you have Hashimoto’s?

Not automatically.

Having Hashimoto’s does not mean that your body no longer needs iodine.

Your thyroid still needs iodine to produce thyroid hormones.

How much you need depends partly on your diet and your individual situation.

That is why it is generally not a good idea to start following a low-iodine diet on your own.

How do you get iodine from your diet?

Iodine is naturally present in several foods.

In the Netherlands, bread is an important source because bakers' salt is often fortified with iodine. Fish, dairy products and eggs can also provide iodine.

So your intake depends greatly on what you normally eat.

For example, if you eat very little bread and dairy, your iodine intake may be different from someone who eats these foods every day.

That still does not automatically mean that you need a supplement.

What about iodine supplements?

This is where I would be cautious.

Iodine supplements can contain relatively high amounts of iodine. Products such as kelp or seaweed supplements can also contain a lot of iodine, and the amount can vary considerably.

With Hashimoto’s, it is therefore not a good idea to start taking a high-dose iodine supplement simply because you have read that iodine is good for the thyroid.

More is not automatically better.

If you are unsure about your iodine intake, discuss it with your doctor or a dietitian.

What about seaweed?

Seaweed is an interesting example.

Some types of seaweed can contain particularly high amounts of iodine.

Eating a normal amount of seaweed as part of your diet is different from taking a concentrated kelp supplement every day.

Because the iodine content can vary so much, it is sensible to be cautious with products specifically marketed as iodine sources or thyroid support.

Can iodine cause Hashimoto’s?

Iodine does not simply cause Hashimoto’s.

Hashimoto’s is an autoimmune disease involving several different factors.

However, very high iodine intake can affect thyroid function and, in some people, may aggravate an existing autoimmune thyroid process or thyroid disorder.

That is different from saying:

“Iodine causes Hashimoto’s.”

It is not that simple.

Should you avoid iodine if you have Hashimoto’s?

For most people, the goal is not to avoid iodine completely.

It is more about getting an appropriate amount.

You therefore do not automatically need to remove all iodine-containing foods from your diet.

And you do not automatically need an iodine supplement either.

The important thing is to consider your overall diet and your individual situation.

What if you take levothyroxine?

Even if you take levothyroxine, iodine remains part of a normal diet.

But replacing iodine with thyroid hormone, or vice versa, is not that simple.

Levothyroxine provides the hormone your body may not be producing sufficiently. Iodine is a raw material that the thyroid uses to produce thyroid hormones.

They are therefore two different things.

If you take levothyroxine, do not change your medication or supplements simply because you have read something about iodine.

The most important thing to remember

Iodine is needed to produce thyroid hormones, but more iodine is not automatically better.

With Hashimoto’s, there is usually no reason to completely avoid iodine, but it is sensible to be cautious with high-dose iodine supplements and products containing large amounts of kelp or seaweed.

Your thyroid does not need an extreme approach.

As with so many things around Hashimoto’s, it is ultimately about the bigger picture: your diet, medication, blood results and how your body responds.