Dr Mark Vanderpump, Consultant Endocrinologist and former President of the British Thyroid Association has given the following advice:

'For people with a properly functioning thyroid iodine is essential as it is required for the production of thyroxine. It is particularly important in women who are pregnant as it is needed to ensure the development of a baby's brain during pregnancy and early life. People who are taking replacement thyroxine (levothyroxine) however do not have a functioning thyroid to absorb iodine and therefore iodine is not required. For patients being treated for hyperthyroidism, taking an iodine supplement is unnecessary and can worsen the condition.'

We also recommend Iodine Facts written by members of the UK Iodine Group; Dr Sarah Bath, Dietician and Prof Margaret Rayman, RNutr., University of Surrey, and endorsed by The British Dietetic Association (BDA).