Expert Advice From Louise O’Connor, Australian Naturopath + Wellness Coach { About the book }

Do The Best Iodine Supplements Supply A Safe Amount of Iodine?

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best iodine supplementsResearch confirms iodine supplements are beneficial for preventing, and treating an iodine deficiency. In addition, iodine is considered the master nutrient for thyroid health. With this in mind, how do you choose the best iodine supplements?

When it comes to choosing the best iodine supplements there is one truth that you need to know.

Iodine supplementation is about balanced intake.

It’s that simple. Iodine is a nutrient that is only normally required in very small amounts. This is the reason most iodine supplements, or thyroid supplements supply trace, or microgram quantities of iodine.

Before we look at how much iodine is safe to take, let’s take a few moments to consider why iodine is beneficial to your thyroid health.

Why Iodine Is Beneficial To Your Thyroid Health

Iodine is the master thyroid nutrient.
Low iodine intake can cause hypothyroidism, swelling of the thyroid, and a reduced ability of the thyroid to produce thyroid hormones.

Iodine is needed for proper thyroid function.
Iodine is used to manufacture the thyroid hormones T3 (triiodothyronine), and T4 (thyroxine). The thyroid acts as a ‘sponge’ and absorbs iodine from the blood to meet ongoing demand for these thyroid hormones. The thyroid hormones are then released into the body to help regulate a wide range of important metabolic processes.

If the thyroid gland fails to produce sufficient thyroid hormones, or there is a decline in thyroid hormone activity within the body, it leads to a wide range of symptoms. Termed hypothyroidism, the two main warning signs are ongoing fatigue, and a colder than normal body temperature.

How Much Iodine Is Safe To Take?

Given the importance of iodine the Australian National Health and Medical Research Council (NHMRC) provide nutritional guidelines on intake. They advise that adults generally need 150 micrograms of iodine per day, while pregnant and breastfeeding women need around 220 micrograms of iodine daily.

The Australian National Health and Medical Research Council (NHMRC), and the US National Institutes of Health have also set the safe upper level of intake. They recommend no more than 1,100 micrograms of iodine per day. In view of this recommendation you should avoid taking high doses of iodine for prolonged periods unless you are doing this in consultation with a trusted healthcare practitioner.

In regards to nutritional supplements, the Therapeutic Goods Administration (TGA) of Australia only approve products that supply no more than 300 micrograms of iodine per day when taken as recommended.

Some Important Iodine Facts To Consider

Nutrient deficiencies are a common issue for those with hypothyroidism. As a general rule, iodine is one nutrient you don’t want to get low in as it’s so critical to your thyroid health.

For this reason, here are some iodine facts that are important to be aware of.

+ A microgram measurement of iodine is abbreviated as ‘mcg’ or ‘µg’. Furthermore, it’s good to know that 1 milligram equals 1,000 micrograms. For example, if you see a supplement supplies 12.5 mg of iodine this is the same as 12,500 micrograms of iodine (which is a very large dose of iodine).

+ Your body does not make iodine. As a consequence, it’s recommended you get this mineral from food sources, or an iodine supplement.

+ Around 80% of your body’s iodine stores are held in your thyroid. When your thyroid has enough iodine it stops absorbing iodine from the blood supply.

+ This mineral is normally only required in trace amounts. Adverse effects are more likely when excessive amounts are taken.

+ Iodine deficiency is a common world health problem. Iodine rich foods should be part of a well-balanced diet.

+ Iodine is critical to overall health, not just the thyroid. For example, iodine plays a role in the immune response, is essential for normal growth and development of a developing baby, and is particularly important to safeguard breast and prostate health.

+ In Australia, iodine supplements, or thyroid supplements that contain iodine normally supply microgram, not milligram quantities of iodine.

What Are The Best Iodine Supplements For Thyroid Health?

Natural health clinics, health shops, and online health websites sell liquid iodine concentrates, Bladderwrack supplements, thyroid health supplements, and single iodine supplements. If a product supplies iodine well above what is generally recommended it’s wise to be cautious, especially if you have a diagnosed autoimmune thyroid disorder.

Studies have shown an iodine overload may trigger an autoimmune flare up. It’s a myth that any amount of iodine will cause a problem. Again, it’s about balanced intake. You can read more here: Is Iodine Safe To Take When You Have Hashimoto’s Thyroiditis?

The best iodine supplements recommend what a safe amount of iodine.

Australian National Health and Medical Research Council (NHMRC) and the New Zealand Ministry of Health (MoH). Nutrient Reference Values for Australia and New Zealand. Iodine. Link

Braun L, Cohen M. Herbs and natural supplements: an evidence-based guide, 3rd ed. Iodine Monograph. Page 614-622. Churchill Livingstone. 2007.

National Institutes of Health. Medline Plus. Herbs and Supplements. Iodine monograph. National Library of Medicine. National Institutes of Health (NIH), USA. Updated 2 January 2013. Link

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  1. I am interested that I am currently taking 4 capsules of 12.5 mg each (!) per day — on recommendation of Naturopath. This is in response to a 24 hour urine sample analysis. In your opinion, how often should this be reviewed to determine whether this high dosage is still necessary and / or healthy?

    • Louise O'Connor says:

      Hi Rosalie, the thyroid acts like a sponge and absorbs iodine rapidly, especially when you are taking a high amount of iodine. You would expect saturation of the gland very quickly. Your iodine levels should therefore be reviewed soon after commencing treatment. It’s a good idea to discuss this question with your Naturopath as they can make recommendations based on your personal health circumstances. Best wishes, Louise O’Connor

  2. Very interesting. Is it possible to get enough Iodine from foods such as fish

    • Louise O'Connor says:

      Hi Marion, I don’t think you can get adequate amounts of iodine from fish. Plus there is a problem with contamination of fish and if the fish is farmed it may be low in iodine. Better dietary sources of iodine is good quality seaweed sourced from clean waters. Seaweed naturally concentrates more iodine than fish. If you are low in iodine I recommend taking an iodine supplement that supplies less than 300 micrograms of iodine per day. Best wishes, Louise O’Connor

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