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29th March 2024

Iodine deficiency, a old (but new) problem…

Iodine deficiency, a old (but new) problem…

Iodine deficiency in Australia (and globally) is not a new phenomenon. In the early 1900s salt was iodised, in the mid 1900s government funded iodine tablets were issued to prevent goiter formation, soon after this iodine-based sanitisers were used in the dairy industry and potassium iodate was added to mass-produced bread. As a nation at risk of deficiency, this should have us covered right? Wrong. Studies show that iodine deficiency has re-emerged in Australia with changes to dairy industry practices (phasing out of iodine-based sanitisers), poor uptake of iodised salt (less than 10% of people choosing iodised salt) and dietary preferences changing (no longer is there 1 or 2 options for salt or bread.. there’s dozens!).

“We have an extraordinary situation in Australia where the community has been dependent upon contamination of a staple food for an essential micronutrient.” (Li et al, 2001).

What increases the risk of Iodine deficiency?

  • Inadequate intake – regional and rural Australians shown to have lower iodine intake compared to urban areas. Iodine is predominantly found in seafood, seaweed, some iodised breads, some iodised salts and eggs. 
  • Geographical/ geological considerations: intense irrigation, high rainfall/ frequent flooding, erosion, non-coastal areas, iodine depleted soils (iodine cycling in many regions is slow and incomplete, leaving soils and drinking water iodine depleted).
  • Increased exposure to many new chemicals (powerful goitrogens) – such as phthalates, parabens and perchlorates.
  • Excessive exercise, or living in hot/ humid climates – as iodine is lost through sweat.
  • Pregnancy and lactation – due to increased thyroid uptake and increased placental transfer.

Women are also at greater risk of deficiency compared to men – due to lactation, fetal development and pregnancy/pregnancies. 

Iodine deficiency can be mild, moderate or severe; and can play out in several ways. 

  1. Thyroid health: Goiter, hypo AND hyperthyroidism, thyroid nodules, an increased risk for thyroid cancer.
  2. Breast health: Fibrocystic breasts, premenstrual breast tenderness (cyclic mastalgia), an increased risk of breast cancer.
  3. Fertility/ pregnancy: Infertility, congenital abnormalities (decreased intelligence, as well as maternal and fetal goiter).
  4. Brain health: Globally, iodine deficiency is considered the single most important cause of preventable brain damage and mental retardation. This is iodine deficiency in it’s most severe form.

“What is alarming is that approximately 60% of the pregnant women in our study displayed urinary iodine levels consistent with mild to moderate iodine deficiency. While the severity of the iodine deficiency in these women is not commensurate with the development of severe neurological consequences in their offspring, we know that even mild maternal iodine deficiency can result in a decrease in cognitive capacity and subtle psychomotor defects in the population.” (Li et al, 2001).

Some creative ways to boost dietary iodine intake… 

As well as adding seaweed (such as dried nori/ wakame) to your diet, opting for iodised salt and bumping up your seafood intake (if you have access to good quality fish that is)… if you have chickens add some seaweed fortified feed to their seed/ grain mix to boost the iodine content in your eggs, you can used seaweed solution in your home garden for your homegrown produce or you can make your own seaweed salt (by adding 1-2 teaspoons or dulse or kelp flakes to ¼ cup to non-iodised salt of choice).

Testing… 

At home iodine patch testing will not tell you if you’re iodine deficient as I’ve discussed in a previous blog, but proper urinary iodine testing is a great way to assess iodine levels. This test is offered through every mainstream Australian pathology company, so ask your GP or practitioner for a referral if you’re concerned about deficiency.

Please don’t self-prescribe iodine, this is one nutrient you must be careful with. 

As iodine is only required in teeny tiny amounts, it’s incredibly easy to take too much. Taking too much iodine is incredibly harmful and can worsen pre-existing conditions (like certain types of thyroid nodules and autoimmune thyroid conditions like Hashimotos). So please, this is definitely one nutrient that both testing and professional guidance on dosing is essential.

Bottom Line

Given that iodine deficiency has re-emerged in Australia, it’s important that as a nation we talk about it, understand how a deficiency can play out, how we can accurately measure it, and most importantly how to ensure adequacy – especially during critical life stages and times of hormonal transition (such as adolescence, pregnancy, breastfeeding and perimenopause!).

Until next time,

Stacey.

Pregnancy & Babies