Even mild #iodine deficiency has noticeable cognitive affects on offspring

A study of 1040 mothers and their offspring published in the Lancet showed that even a mild dietary deficiency of iodine affected the child’s cognitive development.

Iodine is known to be essential for a healthy foetal brain and neurological development. The World Health Organization (WHO) refers to its deficiency as “the single most important preventable cause of brain damage worldwide.” The UK study showed that even mild iodine deficiency in utero was linked to lower IQ and sub optimal reading ability in the offspring.

The children’s scores on the cognitive tests at age 8 to 9 years worsened when deficient group of iodine in the first trimester was lowest. WHO guidelines state that pregnant and breast-feeding women are recommended to have an intake of 250 µg of iodine per day, compared with the recommendation of 150 µg for adults who are not pregnant. It is likely that the most important time to have good iodine intake is the first trimester.

The iodine content of seafood may explain why it has been shown to be great in boosting verbal IQ scores of offspring. As well as seafood, other dietary sources of iodine include dairy products, especially cow’s milk.  However,  organic milk has an iodine content that is 40% lower than conventional milk. Iodized salt is also a good source in some countries but salt is not iodized in the UK. Women should not go overboard with supplements if they feel they are not getting enough iodine; a multivitamin and mineral supplement is fine but high dose supplements such as what are found in kelp and seaweed may provide too much which can be just as harmful

Experts suggested that the study showed that there was a need for a call to action to public-health policy makers in the UK;  Absence of a public-health policy in the face of clear documentation of moderate iodine deficiency and strong evidence of its deleterious effect on the neurodevelopment of children . They also suggested that unmonitored and adventitious dietary iodine sources continue to be relied on.


Lancet . Published online May 22, 2013. Abstract Editorial