Which iodine suits you?

What is iodine?

Iodine (I) is an essential trace element. The thyroid uses it to make the hormones thyroxine (T4) and triiodothyronine (T3), which regulate metabolism, among other things. The body cannot make iodine itself; it has to come from food or supplements.

Iodine is found mainly in sea fish, seaweed, dairy and eggs. In the Netherlands, iodine has been added to baker's salt since 1942. Since 2008 this is no longer a legal requirement but an agreement between the government and the bakery sector; as a result, bread is still the most important source of iodine.

EFSA specifies an adequate intake for adults of 150 µg per day, and 200 µg during pregnancy and breastfeeding. Labels use 150 µg (RI). The safe upper limit for total intake from food and supplements is 600 µg per day.

Iodine and EFSA — what is scientifically recognised?

The following health claims, among others, are authorised for iodine in Regulation (EU) 432/2012:

• Iodine contributes to the normal production of thyroid hormones and normal thyroid function.
• Iodine contributes to normal energy-yielding metabolism.
• Iodine contributes to normal cognitive function.
• Iodine contributes to normal functioning of the nervous system.
• Iodine contributes to the maintenance of normal skin.

The claims apply with a daily intake that provides at least 15% of the reference intake: 22.5 µg iodine per daily dose. The Elke Dag multivitamins and the Organic Sea Kelp reach this threshold. For the Irish sea moss, the iodine content is not stated on the label; we therefore make no iodine claims for that product.

Who may be getting too little iodine?

According to the RIVM (Dutch National Institute for Public Health and the Environment), most adults in the Netherlands get enough iodine. A lower intake is mainly to be expected in:

• People who eat little or no bakery bread, for example on a gluten-free or low-carbohydrate diet.
• Home bakers who bake bread with non-iodised salt.
• Vegans who do not eat dairy, eggs and fish and also eat little bakery bread.
• Pregnant and breastfeeding women, because their requirement is higher.

If you have doubts about your intake or have complaints, have your doctor take a look before you start supplementing yourself.

Iodine at Plenthera and other forms on the market

Elke Dag multivitamins (Vitals) — at Plenthera

Elke Dag, Elke Dag 50+ and Elke Dag Platinum contain 75 µg iodine as potassium iodide per daily dose (50% RI), together with 55 µg selenium. For those looking for a small, precisely dosed supplement, this is the most predictable route. Have a look at the multivitamins.

Organic Sea Kelp (KiKi Health) — at Plenthera

Organic kelp (Ascophyllum nodosum) from European waters, 500 mg per capsule, with 432 µg iodine per capsule (288% RI). That is below the safe upper limit of 600 µg, but well above what most people need from a supplement. So use a maximum of 1 capsule per day, not alongside other sources of iodine, and only after consulting your doctor if pregnant, breastfeeding or with a thyroid condition. Not suitable for children under 11 years.

Organic Irish Sea Moss (KiKi Health) — at Plenthera

Organic Irish sea moss (Chondrus crispus), 500 mg per capsule, 1–2 capsules per day. Sea moss naturally contains iodine, but the content is not stated on the label. It is therefore not a product for managing your iodine intake; do not combine it with other iodine supplements without your doctor's advice.

Other forms on the market

Individual potassium iodide tablets or drops (usually 100–150 µg) are precisely dosed. Lugol's solution contains milligrams of iodine per drop, much more than the daily requirement, and is therefore not suitable as a daily supplement. Non-standardised seaweed products can also contain highly variable, sometimes very high amounts of iodine. We do not currently stock these.

How do you use iodine?

1. First look at your diet: if you eat bakery bread, dairy or fish daily, you usually get enough iodine.
2. Follow the dosage on the label and add up iodine from multivitamins and seaweed products.
3. Keep your total intake below the upper limit of 600 µg per day.
4. With a thyroid condition, thyroid medication, pregnancy or breastfeeding: only use iodine supplements in consultation with your doctor or midwife.
5. If you use levothyroxine, take supplements at a different time, following the advice of your doctor or pharmacist.

Myths and misconceptions about iodine

Myth 1: "The more iodine, the better for the thyroid."

Incorrect. Both too little and too much iodine can disrupt the thyroid. More than you need provides no benefit.

Myth 2: "Seaweed is always a safe, natural source of iodine."

Not automatically. The iodine content of seaweed varies greatly by species and harvest. Choose a product with the content stated on the label and stick to the dosage.

Myth 3: "With iodised salt, everyone gets enough iodine."

For most people in the Netherlands that is true, but those who eat little bakery bread miss out on the most important source. Then it makes sense to check your intake.

Combining iodine with other supplements

• Multivitamins: the Elke Dag line from Vitals contains iodine and selenium. Selenium contributes to normal thyroid function.
• Iron: iron contributes to normal energy-yielding metabolism, just like iodine.
• Algae: when combining with seaweed products, watch your total iodine intake.
• Minerals: the entire mineral range in one place.

Frequently asked questions

How much iodine do I need per day?

EFSA specifies an adequate intake for adults of 150 µg per day, and 200 µg during pregnancy and breastfeeding. Labels use 150 µg (RI). The safe upper limit for total intake is 600 µg per day.

Do I get enough iodine from my diet?

In the Netherlands, most iodine comes from bread baked with iodised baker's salt, and further from dairy, eggs and sea fish. Those who eat little or no bakery bread, for example on a gluten-free diet or when baking at home with non-iodised salt, and also do not eat dairy and fish, get less iodine.

Is kelp a good source of iodine?

Kelp naturally contains a lot of iodine, but the content varies greatly by species and harvest. So choose a product with the iodine content per capsule stated on the label. KiKi Health Organic Sea Kelp provides 432 µg per capsule; that is well above the reference intake, so do not take more than 1 capsule per day and do not combine it with other sources of iodine.

Can I use iodine during pregnancy?

During pregnancy and breastfeeding, the requirement is higher (200 µg per day). Consult your midwife or doctor about a supplement; high-dose seaweed products are not suitable then.

Can I use iodine with a thyroid condition?

With a thyroid condition or thyroid medication: only use iodine supplements in consultation with your doctor. Too much iodine can worsen existing thyroid problems.

Why is iodine often combined with selenium?

Both are involved with the thyroid: iodine contributes to the normal production of thyroid hormones and normal thyroid function, and selenium contributes to normal thyroid function. The Elke Dag multivitamins from Vitals contain both.

Sources

• Regulation (EU) 432/2012 — authorised health claims for iodine and selenium.
• EFSA NDA Panel (2014). Scientific Opinion on Dietary Reference Values for iodine. EFSA Journal 12(5):3660.
• EFSA Scientific Committee on Food (2002/2006). Tolerable Upper Intake Level of iodine.
• RIVM (Dutch National Institute for Public Health and the Environment) — iodine intake of the Dutch population.
• Pearce EN et al. (2016). Consequences of iodine deficiency and excess in pregnant women: an overview of current knowns and unknowns. Am J Clin Nutr 104(Suppl 3):918S–923S.