Iodine – the forgotten nutrient
You probably haven’t thought much about Iodine, and you may not know that for the past 6 years commercial bread in Australia has been fortified with Iodine, making it a major source of Iodine in our diets.
Why fortify bread with Iodine?
In Australia and New Zealand, the soil where we grow our fruits and vegetables and graze our livestock is very low in Iodine, meaning that our food supply also doesn’t contain much Iodine. This has resulted in fairly high rates of Iodine deficiency in our general population. The Australian Institute of Health and Welfare reported that prior to fortification, up to 25% of teenage girls had inadequate intake and that 43% of Australian adults tested demonstrated inadequate intakes of Iodine.
Why is Iodine important?
- Iodine is an essential trace mineral which is important for making thyroid hormones. Low levels of Iodine can result in Hypothyroidism or Iodine Deficiency Disorders (IDD). Thyroid hormones regulate metabolism and are important for normal growth and development, particularly of the brain.
- Goitre is common in adults with very low levels of Iodine intake. Symptoms include an enlarged thyroid gland, dry skin, fatigue and hair loss.
- Iodine requirements increase by around 50% in pregnancy to support the growth and development of the baby. Low Iodine intake in pregnancy can result in learning difficulties, mental retardation and stunted growth. In Australia, it is recommended that pregnant and lactating women take a supplement containing 150mcg Iodine per day. If you are concerned it is advisable to talk to you doctor about your iodine levels and your personal need a supplement.
How much Iodine do we need?
Over a lifetime only 1 teaspoon of Iodine is required, however, we don’t store Iodine so small regular intakes are important. The National Health and Medical Research Council recommend a daily intake of 150mcg per day for adults and 220mcg (150mcg supplemental) per day for pregnant women.
Food sources of Iodine.
- Bread: It is mandatory for Iodised salt to be used in all yeasted bread in Australia since October 2009, meaning bread is now a major source of Iodine. Exceptions include bread mixes and bread labelled as “organic”
- Seafood: Fresh fish, tinned fish, shellfish and seaweed are all good source of Iodine
- Supplementation: An Iodine supplement is assessed on an individual basis, depending on your specific requirements. Many pregnancy and breast feeding vitamins contain Iodine and it is recommended that pregnant and breastfeeding women consult their doctor before commencing supplementation.
- Iodised Salt: Iodine fortified salt is widely available, however, use of salt in general has decreased due increased awareness of health concerns, such as high blood pressure. The increased availability of gourmet salt products, such as “Sea Salt” and “Himalayan Pink Salt”, which are sometimes mistakenly spruiked as healthier choices by health gurus, has also reduced the use of Iodised salt.
- Dairy: Historically milking equipment was cleaned with Iodine, which ensured dairy as a source of Iodine in the Australian diet. This has now been phased out and Dairy products are no longer as high in Iodine.
Iodine is important for general health and wellbeing and particularly important in pregnancy to support growth and development of the baby. Since most Australians get more than enough salt in their diet and considering the health concerns of a diet high in salt I don’t suggest that you start adding salt to your food just to increase your Iodine. However, if you are someone who limits the amount of bread you eat, makes your own bread (from a mix or from scratch) or buys “organic” bread that is not fortified you may want to consider other sources of Iodine in your diet or if you are concerned, consult your doctor.