Iodine
Iodine is an essential trace element required for thyroid hormone (T3 & T4) synthesis; severe deficiency causes cretinism & goiter, & adequate intake during pregnancy & early childhood is critical for normal neurodevelopment.
Evidence last reviewed: 04 Apr 2026
The evidence indicates that iodine is essential for thyroid hormone production and child neurodevelopment, particularly in areas of severe deficiency. However, studies show inconsistent results regarding supplementation benefits in mildly deficient populations, highlighting a need for more robust research.
Child development outcomes (cretinism prevention, motor/cognitive) in relation to prenatal iodinePregnant women and their offspring across iodine-status populations · systematic review of RCTsLow
Systematic review of 8 RCTs found that in areas of severe iodine deficiency, supplementation reduced cretinism risk & showed some motor development benefits; in mild-to-moderate deficiency areas, no RCTs provided data on childhood cognitive or developmental outcomes; effects on maternal thyroid function were inconsistent.
Thyroid function & child neurodevelopment in mildly deficient pregnancyPregnant women with mild-to-moderate iodine deficiency · systematic review and meta-analysis of RCTsLow
A systematic review of 10 RCTs & 23 observational studies found inconsistent effects of iodine supplementation on maternal or infant TSH & no significant improvement in childhood cognitive, language, or motor scores; authors concluded evidence is insufficient to support universal supplementation in mild-to-moderate deficiency regions but supplementation remains important in severe deficiency.
Thyroid & Hormonal Support
Iodine & selenium are combined to support thyroid function & hormonal balance. Iodine is essential for thyroid hormone production, while selenium supports thyroid health & antioxidant defense.
Forms & usage▾
Take 150 mcg daily, ideally through iodized salt or supplements, especially during pregnancy.