Moms-to-be, note! Mild iodine deficiency during pregnancy can lower the IQ of your baby, a study of 1,000 UK families has warned.
The research showed lower intelligence quotients and reading scores in primary school students whose mothers had had too little iodine while pregnant.
Experts advise women of child-bearing age to maintain iodine in their diets by eating dairy products and fish, 'BBC News' reported.
Researchers say iodine is essential for the development of the brain as it is needed to build some of the body's hormones. A severe deficiency is the leading cause of preventable brain damage in the world.
However, the impact of low-level deficiency was previously unknown.
Researchers at Surrey and Bristol Universities looked at iodine levels in urine samples taken from pregnant women in south-west England.
Iodine deficiency was common - affecting two-thirds of women, according to the study published in the journal Lancet.
Their kids went on to have slightly lower IQs at the age of eight and worse reading ability aged nine.
"We saw a three-point IQ difference between children who were born to mothers with low iodine in early pregnancy and children who were born to mothers above the cut-off," Dr Sarah Bath said.
Researchers said this "may prevent a child reaching their full potential" and was an "important public health issue."
"Our advice is to make sure they have enough iodine intake, and take additional iodine in safely, probably from food - dairy products, fish," Prof Margaret Rayman said.
