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Study finds worrying deficiency in iodine levels

posted 12/04/2011   expires 12/07/2011

New research by Royal Free doctors suggests that many children and adults in the UK could be deficient in iodine, a trace element important for brain development.

Women of childbearing age are most at risk as even a mild deficiency could harm a baby’s developing brain.

The study, carried out for the British Thyroid Association, involved more than 700 teenage girls at nine UK centres and found that more than two-thirds had a deficiency.
Dr Mark Vanderpump, consultant physician and honorary senior lecturer in endocrinology at the Royal Free, led the team and presented his findings at the Society for Endocrinology annual conference today (Tuesday 12 April). Dr Mark Vanderpump

His research linked deficiency to children drinking less milk, which is a good source of iodine. He said: “Children used to consume a lot more milk. We found that there was a lower dietary intake of milk in the diet of the girls who had the lowest urine iodine levels and this may be an important factor in why they were so iodine-deficient.”

 Dr Vanderpump called for a full review of the country’s iodine status and for recommendations to safeguard public health.

He said: “We need to look into this now to decide whether public health bodies need to step in. We are very concerned as the consequences of iodine-deficiency are grave: iodine-deficient communities score lower in IQ tests, and even mild iodine-deficiency during pregnancy can cause mental impairment in children.”
“The World Health Organisation has been campaigning for at-risk countries to add iodine to their salt. If it turns out we do have a problem, this could be the most viable solution.”

Iodine is an essential trace element which helps the thyroid gland function properly. Most people get iodine from their diet. Good sources are dairy products and seafood. 
Notes to editors
1. For more information, contact Soraya Madell on 020 7830 2963 or email:

2. See BBC News Online article on the research.

3. The study was funded by the Clinical Endocrinology Trust. It involved measuring urinary iodine levels in samples from 737 girls aged 14 to 15 from nine UK centres. Some 69 per cent of the samples were deficient in iodine and 18 per cent showed very low levels. 
4. Iodine-deficiency is the most common cause of preventable mental impairment worldwide. The World Health Organisation has conducted a global programme of salt iodisation since 1993. The UK is yet to join this programme and does not require salt producers to iodise their salt.

5. The Royal Free is Dr Foster’s ‘large trust of the year’ for 2010. Our services have been rated “excellent” for the third year running, most recently by the Care Quality Commission. The trust attracts patients from across the country and beyond to its specialist services in liver, kidney and bone marrow transplantation, surgery for hepatopancreatobiliary (HPB) conditions, clinical neurosciences, renal, HIV, infectious diseases, plastic surgery, immunology, vascular surgery, cardiology, amyloidosis and scleroderma and are a member of the academic health science partnership UCL Partners. For further information, visit
6. The Society for Endocrinology annual conference is Britain’s biggest scientific meeting on hormones and takes place in Birmingham from 11-14 April 2011. See the society's website for a full programme.