Food and Behaviour Research

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Iodine as Essential Nutrient during the First 1000 Days of Life

Velasco I, Bath SC, Rayman MP. (2018) Nutrients. Mar 1;10(3).  pii: E290. doi: 10.3390/nu10030290. 

Web URL: View this and related abstracts via PubMed here, Free full text of this article is available online


Iodine is an essential micronutrient incorporated into thyroid hormones. Although iodine deficiency can lead to a broad spectrum of disorders throughout life, it is most critical in the early stages of development, as the foetal brain is extremely dependent on iodine supply.

During the last two decades, our understanding of thyroid physiology during gestation has substantially improved. Furthermore, thyroid hormone receptors have been identified and characterised in placental and embryonic tissues, allowing us to elucidate the maternal-foetal transfer of thyroid hormones.

Experimental studies have demonstrated that the cyto-architecture of the cerebral cortex can be irreversibly disturbed in iodine deficiency causing abnormal neuron migratory patterns which are associated with cognitive impairment in children.

In this context, the role of iodine as key factor in the programming of foetal and infant neurodevelopment, needs to be revisited with a special focus on areas of mild to moderate iodine deficiency.

The objective of this review is to summarize the available evidence from both animals and human studies, for the effect of iodine deficiency (particularly, of maternal hypothyroxinemia) on brain development and neurological or behavioural disorders, such as lower intelligence quotient (IQ) or attention deficit hyperactivity disorder (ADHD).


This review highlights the critical importance of adequate iodine for normal brain development.

As FAB Research followers will know, two of these authors (Professor Margaret Rayman and Dr Sarah Bath) reported in 2013, using from a large UK birth cohort study, that mild-to-moderate iodine deficiency affected around 2/3 of mothers-to-be - and that this predicted significant reductions in the verbal IQ and reading of their children at 8 years of age.  See:
Last year, a large Nowegian study reported similar findings:
The UK is one of the only developed countries with no public health policy on iodine (such as the mandatory iodisation of salt) - and as the main dietary sources are milk and dairy products, and fish and seafood, anyone following vegan diets (or any other diets that exclude these foods) are at particular risk of iodine deficiency. See:
For more information on the importance of iodine in pregnancy see also: