Food-based iodine during pregnancy important for child brain development

By Tim Cutcliffe contact

- Last updated on GMT

© iStock/ Antoine2K
© iStock/ Antoine2K

Related tags: Iodine, Thyroid

Low levels of maternal iodine may be linked to reduced brain development at age three, a new study has suggested.

The study, published in The Journal of Nutrition,​ was a collaboration between the Norwegian institute of Public Health, Oslo and Akershus University College of Applied Sciences and TINE SA and used data from the Norwegian Mother and Child Cohort Study (MoBA).

They found that children whose mothers had low dietary iodine intakes during pregnancy were more likely to experience various symptoms of impaired brain development.

“Maternal iodine intake below the Estimated Average Requirement (EAR) during pregnancy was associated with symptoms of child language delay, behaviour problems, and reduced fine motor skills at 3 y of age,”​ concluded lead author Marianne Abel from the Research and Development department of TINE SA.  

In the main analysis, the study evaluated iodine intake solely from food. Participants were divided into those consuming either less than, or more than 160 micrograms per day (ug/d), the EAR recommended by the National Academy of Medicine (formerly the Institute of Medicine)

The study also observed a dose –response relationship between maternal iodine intake and behavioural problems, with odds ratio for this outcome rising particularly steeply for dietary intakes below 100 ug/d.

“The results of this study emphasize the urgent need for preventing inadequate iodine intake in women of childbearing age to secure optimal brain development in children,” ​recommended Abel.

No benefit from supplements

The team also carried out separate analysis on mothers taking iodine supplements of up to 200 ug/d.

The results showed no evidence of a protective effect of iodine supplementation during pregnancy,” ​commented the researchers.  

For mothers in the low intake group (<160 ug/d), supplementation was linked to negative effects.

“In those reporting first use in gestational weeks 0–12, supplement use was associated with an increased risk of externalising behaviour problems,” ​reported the researchers.

Similarly, starting supplementation in the second trimester was linked to a higher risk of internalising behaviour problems.

The study authors speculated on various possible reasons for the lack of beneficial, and potentially harmful, effects of supplementation.

“Initiating supplement use during pregnancy might be too late and may also provide less iodine than needed to compensate for the effects of a depleted iodine store on thyroid function​,” they suggested.

“A sudden increase in iodine intake [from supplements], although modest and within the recommendations, might also lead to a ‘stunning effect,’ with transient inhibition of maternal or foetal thyroid hormone production.”

Iodine intake measurement

In the study, researchers used iodine consumption calculated from a Food Frequency Questionnaire (FFQ) (specifically designed for MoBa) to measure intake, rather than Urinary Iodine Concentration (UIC). Validation studies showed a good correlation between the two exposure measures, indicating that FFQ is an adequate long-term measure for iodine status.

“FFQ correlation coefficients for the calculated iodine intake and major iodine food sources were higher than for most other foods and nutrients, indicating a regular consumption pattern of food items containing iodine,”​ wrote the researchers.

Long-term dietary intake

The researchers emphasised the importance of long-term, rather than short-term iodine status; and that securing long-term adequate dietary (rather than supplemental) intake before pregnancy is essential to promote healthy brain development in children.

Source: The Journal of Nutrition
Volume 147, issue 7. Pages 1314-1324   doi: 10.3945/jn.117.250456
“Suboptimal Maternal Iodine Intake Is Associated with Impaired Child Neurodevelopment at 3 Years of Age in the Norwegian Mother and Child Cohort Study”
Authors: Marianne H Abel, Anne-Lise Brantsaeter et al

Related news

Show more

Related products

show more

20 Years Palm Tocotrienols Brain Health Research

20 Years Palm Tocotrienols Brain Health Research

ExcelVite Sdn. Bhd. | 25-Sep-2019 | Technical / White Paper

Research of Vitamin E tocotrienol in brain health and neuroprotection began twenty years ago.
Today, other health benefits have been discovered...

HRB are ideal probiotics for human health

HRB are ideal probiotics for human health

Morinaga Milk Industry Co., Ltd. | 19-Sep-2019 | Technical / White Paper

Evidence is accumulated that the physiological benefits of probiotics bifidobacteria are not only strain-specific but also dependent on their residential...

What do you know about Sulphur?

What do you know about Sulphur?

LEHVOSS Nutrition– Gee Lawson | 12-Sep-2019 | Data Sheet

Sulphur plays an important role in several body functions including support of connective tissue, skin health, detoxification, immunity, and metabolism....

Related suppliers

Follow us

Featured Events

View more

Products

View more

Webinars