Did giving iodine pills to pregnant moms help their kids' brains?
Iodine Supplementation in Mildly Iodine-Deficient Pregnant Women Does Not Improve Maternal Thyroid Function or Child Development: A Secondary Analysis of a Randomized Controlled Trial
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Iodine supplementation didn't improve child IQ—even though it raised maternal iodine levels beyond safe limits.
Public health guidelines have long promoted iodine supplements for pregnant women, assuming cognitive benefits. This study shows no benefit despite clear biological changes (lower thyroid hormones, excess iodine).
Practical Takeaways
If you're pregnant and live in a country with iodized salt (like the U.S. or Thailand), skip extra iodine supplements unless your doctor confirms a true deficiency.
Not medical advice. For informational purposes only. Always consult a healthcare professional. Terms
Surprising Findings
Iodine supplementation didn't improve child IQ—even though it raised maternal iodine levels beyond safe limits.
Public health guidelines have long promoted iodine supplements for pregnant women, assuming cognitive benefits. This study shows no benefit despite clear biological changes (lower thyroid hormones, excess iodine).
Practical Takeaways
If you're pregnant and live in a country with iodized salt (like the U.S. or Thailand), skip extra iodine supplements unless your doctor confirms a true deficiency.
Publication
Journal
Frontiers in Endocrinology
Year
2020
Authors
Nicole J. E. Verhagen, S. Gowachirapant, P. Winichagoon, M. Andersson, A. Melse-Boonstra, M. Zimmermann
Related Content
Claims (6)
For pregnant women with mild iodine deficiency, taking a 200 μg iodine supplement daily does not improve their child's thinking or movement skills by age 5.7, and may be linked to slightly lower motor skills at age 2, suggesting no overall advantage for brain development.
A study found that giving iodine to pregnant women did not lead to a measurable increase in their children's IQ scores at age 5.7, but this may be because the study did not include enough participants to detect a small but meaningful difference.
Taking standard iodine supplements during pregnancy can raise iodine levels in urine beyond the safety threshold recommended by the WHO, even in women who are only mildly deficient.
In pregnant women with mild iodine deficiency, taking 200 micrograms of iodine daily is linked to a small but measurable reduction in the levels of thyroid hormones called free and total thyroxine during the later stages of pregnancy.
Giving iodine supplements to pregnant women with mild iodine deficiency does not reduce the occurrence of isolated hypothyroxinemia or subclinical hypothyroidism, even when urinary iodine levels rise, suggesting the supplements do not resolve the underlying thyroid hormone imbalance.