Iodine deficiency

The soil of New Zealand is deficient in iodine, and as a consequence our diet is deficient in this important element, as most of what we eat is grown in New Zealand.

A lack of iodine in the diet can affect us at any stage of our lives, as it is vital for normal growth and development. A good intake of iodine is particularly important during pregnancy as a lack of iodine may result in brain damage and an increased potential for still birth and poor pregnancy outcomes.

Once born, if the diet remains low in iodine then babies and children may  develop goitre, which is a swelling of the thyroid gland in the neck, as the body attempts to lessen the effects of the lack of iodine in the diet.

Adults at any stage of their life may also develop goitre, which may result in tiredness, inability to function normally, and impaired brain activity.

Natural sources of iodine are commonly found in eggs and fish, particularly shellfish, and also found in seaweed and other foods sourced from the sea. 

In New Zealand, salt has been supplemented with a small amount of iodine since 1924. The concentration was increased in 1938, which resulted in a dramatic lowering of the number of children with goitre and poor mental development as a result.

Recent surveys in New Zealand have demonstrated that once again our iodine level is not at the ideal level.  As a consequence of this it is now recommended that all women who are pregnant or contemplating pregnancy address this by taking an iodine supplement and continuing this supplementation whilst breastfeeding to ensure that their baby receives an adequate level during this period of growth and development.

For all other people living in New Zealand, it is important to ensure that their diet contains iodine, and the availability and affordability of sushi is helpful.  Iodised salt should be used in moderation, as the preferred salt for table and cooking use.  This is available as rock salt as well as fine salt. Although moderate salt intake is good dietary advice, a small amount of iodised salt seasoning your food may be helpful.  As with all foods, too much of anything doesn’t necessarily mean better health, so avoid use of supplements containing large amounts of salt or iodine.

See your community pharmacist for advice about your diet, and the need for supplementation, particularly if you believe the diet of you or your family may be deficient in this vital element.  Your pharmacist will be able to determine if your diet is adequate in iodine, what supplements are safe and appropriate for you to use, or if you need referral to a doctor or dietician.