Iodine is a nutrient that is sadly often forgotten. You probably know it better as something in certain disinfectants used to clean a wound or gargle with when you have a throat infection (staining your skin in the process!). Its role as an essential nutrient for our bodies has not received just attention. Iodine is essential for thyroid function (and important gland in the body) and although we need only tiny amounts, a shortage affects the production of thyroid hormones and knock on implications for metabolism, growth and development.
When it comes to babies and young children, getting enough iodine is critical to development, especially brain development. So much so that when we look worldwide, iodine deficiency is the biggest single cause of preventable brain damage. Babies and young children who fail to get enough iodine will have lower IQs and in more severe cases brain retardation and stunted growth, among other problems. In Australia, that more severe end of this spectrum is thankfully unusual, but mild to moderate iodine deficiency is much more common, especially in New South Wales and Victoria.
Part of the reason for this is that the level of iodine in soils where we grow our food is low, we don’t eat as much seafood as we should and these are major sources of iodine, and many people have stopped using iodised table salt in favour of sea salt or cutting down salt – an important health measure in itself.
The Nutrient Reference Values for Australia and New Zealand (NHMRC) recommend the following daily intake of iodine:
Pregnant and breastfeeding women need more, as they have their own iodine requirements to meet, as well as those of their developing or feeding little one.
Babies who are breastfed rely on mum’s breast milk to supply iodine and that in turn depends on mum’s diet. That is why you’ll find most breastfeeding multivitamin supplements will include iodine.
For babies whom are bottle fed, it is essential that the infant formula contains the right amount of iodine to fulfil their need.
Once solids and other foods are introduced, the best sources of iodine include seafood (although take care to avoid fish know to be higher in mercury contamination, for example swordfish, orange roughy and ling) and seaweed. Canned fish is a good option, providing iodine and low levels of mercury.
Eggs, dairy, vegetables and meat can also provide some iodine, but levels are highly dependent on the iodine content of the soil used to grow the food or feed the animal. These foods are therefore unreliable sources of iodine.
If you are pregnant or trying to get pregnant, or breastfeeding, the NHMRC recommends a supplement of 150 μg a day. If you are already taking a multi-vitamin and mineral supplement, check the level of iodine in the product before taking any additional supplements. Most supplements today do contain enough iodine.
For formula fed babies, check the level of iodine in the formula is adequate, to match the daily requirements listed above.
After infancy, children continue to require iodine and so ensure you include seafood at least twice a week, consider including seaweed (e.g. sushi is a great way to do this) and use an iodised salt when you do use any salt when cooking at home.
If you are unsure as to whether you or your family are getting enough iodine, speak with your doctor or dietitian for further advice.
Article provided by Dr Joanna McMillian