FAQ: Iodine in pregnancy

Did you know that if you’re pregnant, you should be taking an iodine supplement? Tiffany Brown explains why.

 

What are some sources of iodine?

Natural food sources of iodine are mainly found in the sea, where the element is concentrated in marine products like seafood and seaweed. Sushi has been shown to provide reasonable iodine, due mostly to the seaweed (nori) wrapper. The amount we can obtain from other food sources of iodine, such as meat and dairy products, varies due to the condition of our soils, influenced by natural geology as well as human interventions by irrigation and fertilisers. If a nutrient is not present in the soil, then it cannot be present in the food, and NZ soils tend to be low in iodine.

In 2009, the government developed a strategy to address low iodine levels in the population as a consequence of low-salt diets and non-iodised salt. By fortifying commercial breads with the mandatory inclusion of iodised salt in the ingredients, significant improvements in iodine levels followed, according to the 2016 New Zealand Total Diet Study. It’s worth noting that if you avoid commercial bread products, you may still be low in iodine, if you’re not getting it from other sources. Reliable natural sources of iodine include:

  • Bread fortified with iodine
  • Seafood
  • Seaweeds, including kelp
  • Salts (check the labels carefully as not all salts contain iodine)

 

What about iodine in pregnancy?

The need for iodine increases in pregnancy while we supply our babies with all the nutrition they need as well as keeping ourselves topped up. Sufficient iodine in pregnancy can also increase your baby’s IQ as it is essential for the growth and development of the brain. And deficient iodine status in pregnant mothers is the leading cause of preventable intellectual disability in children.

 

Why is iodine important?

Iodine is one of the many chemical elements our bodies need but cannot make. Only a small amount of it is required for normal function but iodine is detected in every organ and tissue in our body. Iodine is essential for thyroid function and efficient metabolism, and there is increasing evidence that links low iodine with numerous diseases including cancer.

 

How much iodine do I need in pregnancy?

The MOH makes the following specific recommendation for iodine intake during pregnancy and breastfeeding: During pregnancy and while breastfeeding, choose foods that are high in iodine and take an iodine tablet every day. Foods that are high in iodine are well-cooked seafood, milk, eggs, some cereals, and bread. Take one 0.150 milligram (mg)/150 micrograms (mcg or μg) iodine-only tablet every day when pregnant and breastfeeding. You can buy iodine tablets at pharmacies (or at a lower cost when prescribed by your midwife, GP, or nurse practitioner — talk to them to find out more).

 

What are some side effects of taking iodine?

Supplemental iodine is likely safety to take on a short-term basis, although it can cause significant side effects in some people, including nausea and stomach pain, runny nose, headache, metallic taste, and diarrhoea. Iodine supplementation is possibly unsafe to take on a long-term basis, so talk to your GP.

 

I’m breastfeeding. Do I still need to worry about iodine intake?

Iodine is also important when breastfeeding, but don’t give up on natural iodine food sources once your baby is born. A 2016 study found no difference in the effect on breastmilk when comparing mothers who didn’t take any supplements at all to those who took either potassium iodine or multivitamin supplements.

 

How much iodine do i need when not pregnant or breastfeeding?

The Ministry of Health (MOH) established guidelines in 2006 of iodine balance at intakes over 100 micrograms (mcg) per day, but not below 40mcg per day, with an upper limit of 1,100mcg per day for adults. For children, iodine doses should not exceed 200mcg per day for children 1 to 3 years old, 300mcg per day for children 4 to 8 years old, 600mcg per day for children 9 to 13 years old, and 900mcg per day for adolescents 14 to 18 years old.

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