Iodine deficiency 'may lower children's IQ'
22 May 2013 Last updated at 09:29 BST
Mild iodine deficiency during pregnancy could be dimming the intellect of some babies born in the UK, say researchers.
Their study of 1,000 families, published in the Lancet, showed lower IQs and reading scores in primary school pupils whose mother had had too little iodine while pregnant.
Academics advise women of child-bearing age to maintain iodine in their diets by eating dairy products and fish.
Women were warned not to take seaweed pills, as they contain too much iodine.
Matthew Hill reports.