ADDED VALUE

Should our food be fortified with vitamins and minerals?

This week: salt MOST countries have made it compulsory to add iodine, needed for the production of thyroid hormones, to food such as bread and salt. There is no such requirement in the UK. ‘The cost-benefit analysis is hugely in favour of adding iodine to salt in the UK — but less than 5 per cent is,’ says John Lazarus, a professor of clinical endocrinology at Cardiff University.

‘If you do not eat sea fish, shellfish, seaweed or dairy products, you might not get enough iodine in your diet.’

Official figures show that around two-thirds of pregnant women in the UK are deficient. The requirement for iodine increases during early pregnancy partly because of the transfer of maternal iodine to the foetus. ‘This could lead to a very significant drop in IQ measured in children before the age of nine,’ says Professor Lazarus. THE DOWNSIDE: For susceptible people eating too much iodine can cause the thyroid gland to overproduce thyroid hormones, which leads to symptoms such as a rapid heartbeat and insomnia. ‘Iodine in salt could also send a mixed message that salt is good for you,’ says dietitian Ursula Arens.