Delayed neurobehavioral performance was observed in 36% of children in Group 3, and 25% of children in Group 2, and none in Group 1.

"A delay of 6-10 weeks in iodine supplementation of hypothyroxinemic mothers at the beginning of gestation increases the risk of neurodevelopmental delay in the progeny. Public health programs should address the growing problem of iodine deficiency among women of gestational age in developing and industrialized nations." (more below)

The above slide accompanies the study, "Delayed Neurobehavioral Development in Children Born to Pregnant Women with Mild Hypothyroxinemia During the First Month of Gestation: The Importance of Early Iodine Supplementation". The downloadable PDF is available here.

Iodine and Children

* Iodine deficiency in children and adolescents is often associated with goiter. The incidence of goiter peaks in adolescence and is more common in girls. School children in iodine-deficient areas show poorer school performance, lower IQs, and a higher incidence of learning disabilities than matched groups from iodine-sufficient areas. A meta-analysis of 18 studies concluded that iodine deficiency alone lowered mean IQ scores in children by 13.5 points. In-other-words, having full iodine sufficiency has been shown to increase IQ by up to 13.5 points.

* Drinking fluoridated water consumed by women yields children with lower IQs, why? Fluoride competes with iodide.

* Lower IQ of 12-13.5 points are seen in iodine deficient populations, whereas iodine supplementation before or during early pregnancy generally increases developmental scores in young children by 10-20%.

* The IQ of a child is set between age 2-3. Therefore, it is essential to keep giving nursing mothers iodine until the child is weaned.

How adding iodine to salt made America smarter
Monday, Feb 10 2014

* The U.S. introduced iodized salt in 1924

* A new study compares IQ results of people in iodine deficient areas before and after iodized salt

* Americans born in iodine deficient areas showed an IQ increase of 15 points after 1924

* Iodine deficiency causes goiter and mental and physical retardation in infants

A new study indicates that Americans gained up to 15 IQ points after the addition of iodine to salt became mandatory.

In an effort to prevent goiter related to iodine deficiency, authorities ruled that iodine be added to U.S. salt products in 1924.

The iodine, in addition to eliminating goiter, appears to have had an unexpected result: smarter Americans.
In a report published in the National Bureau of Economic Research, James Freyer, David Weil and Dimitra Politi examined data from about two million enlistees for World War II born between 1921 and 1927, comparing the intelligence levels of those born just before 1924 and those born just after.

To do this, they looked to standardized IQ tests that each recruit took as a part of the enlistment process.
While the researchers didn't have access to the test scores themselves, they had another way of gauging intelligence levels: smarter recruits were sent to the Air Forces, while the less intelligent ones were assigned to the Ground Forces.

Next, the economists worked out likely iodine levels in different cities and towns around America using statistics gathered after World War I on the occurrence of goiter.

Matching the recruits with their hometowns showed researchers that the men from low-iodine areas made a huge leap in IQ after the introduction of iodine.

The men born in low-iodine areas after 1924 were much more likely to get into the Air Force and had an average IQ that was 15 points above that of their slightly older comrades.

This averages out to a 3.5 point rise in IQ levels across the nation.

The World Health Organization backed up these results saying:

'For iodine-deficient communities, between 10 and 15 IQ points may be lost when compared to similar but non-iodine-deficient populations.'

Iodine comes from food sources, and is found in seafood and foods grown in coastal areas with high levels of iodine in the soil.

Mountainous and inland areas are often very low in the nutrient, meaning food grown there doesn't have enough iodine.

Today, iodine deficiency is the leading cause of preventable mental retardation in the world. The condition, known as cretinism, was also common in the U.S. until the introduction of iodized salt. [And since Americans have reduced or eliminated iodized table salt, sub-clinical and clinical hypothyroidism is on the rise, and so are stupid movies, TV shows, and commercials, and antisocial behavior... coincidence? – Don]

Originally, U.S. authorities wanted to reduce the incidence of goiter, but research since that time has shown that iodine plays an important role in brain development, especially during gestation.

The World Health Organization estimates that two billion people worldwide are at risk of iodine deficiency. And it's not just a Third World problem – the WHO reports that only 27 per cent of households in Europe have access to iodized salt.

The researchers say that iodine may also be a cause of the so-called Flynn Effect, the steady rise in IQ that's been ongoing since the 1930s. But the Flynn Effect works both ways, and now, since people in the U.S. have been avoiding table salt, which was the way iodine became part of our diet, IQs will be dropping, and cognition will be negatively affected. See How Adding Iodine to Salt Made America Smarter.

So the take-away here is to be iodine sufficient before conceiving. It can be problematic to try and correct a low iodine level once pregnant due to bromine detox; not impossible, but much easier done before conceiving. And your child will thank you for it.