Iodine deficiency

The Editorial Executive Committee welcomes letters, which should be less than 250 words. Before a decision to publish is made, letters which refer to a published article may be sent to the author for a response. Any letter may be sent to an expert for comment. When letters are published, they are usually accompanied in the same issue by their responses or comments. The Committee screens out discourteous, inaccurate or libellous statements. The letters are sub-edited before publication. Authors are required to declare any conflicts of interest. The Committee's decision on publication is final.

Editor, – I am an endocrine surgeon working with a diverse overseas-born population. I have been checking the iodine nutritional status of my goitre patients recently, as iodine deficiency may be more common in Australia than previously thought. Only two or three patients out of 54 tested with normal iodine levels on 24-hour urinary iodine testing. One notable exception was a patient with 45 times the normal daily excretion. On questioning, she had not had recent IV contrast media or amiodarone, but had consumed a herbal cough mixture. The contents of the medicine are unclear.

Iodine does not appear to be listed on the box. The dose of half to one tablespoon without reference to frequency or age concerns me. Prescribers (and patients) need to be aware that herbal remedies can be hazardous. Patients with pre-existing goitre can become thyrotoxic if exposed to even a modest supranormal iodine load. Those with thyroid cancer who are given iodine by well-meaning naturopaths may delay or reduce the effectiveness of radioactive iodine therapy.

Peter Campbell
Endocrine Surgeon
Liverpool, NSW