Iodine has been recognised for some time now as being an important trace element. Due to its low content in local
soil, it is difficult to achieve adequate levels of iodine in New Zealand. As a public heath measure, iodine was added
to salt, and more recently iodised salt is now required to be used in most commercially available breads.
Iodine supplements could in theory be taken by non-pregnant patients who may be iodine deficient, but it would be
more appropriate to advise these patients to enhance their dietary iodine intake by the use of iodised salt, bread,
seafood, etc, much in the same way as patients are generally advised to achieve their recommended vitamin C intake through
diet rather than by supplementation.
Euthyroid goitre (simple, non-toxic goitre) is a non-cancerous hypertrophy of the thyroid without hyperthyroidism,
hypothyroidism or inflammation. Except in severe iodine deficiency, the thyroid function is normal and patients are
asymptomatic apart from an obviously enlarged, non-tender thyroid.1 The diagnosis is made clinically along
with normal thyroid function.
Euthyroid goitre is most frequently noted at puberty, during pregnancy and at menopause. The cause at these times
is usually unclear. Known causes include intrinsic thyroid hormone production defects and, in iodine-deficient countries,
ingestion of foods that contain substances that inhibit thyroid hormone synthesis such as raw brassicas e.g. broccoli,
cauliflower or cabbage. Other causes include the use of drugs that can decrease the synthesis of thyroid hormone e.g.
Treatment of euthyroid goitre is directed at the underlying cause, but partial surgical removal may be required for
very large goitres. Iodine supplements are not routinely recommended. Advice about adequate iodine intake through dietary
measures is appropriate in the majority of cases.
N.B. Measurement of iodine levels to detect deficiency is not recommended.