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Randomised trial of iodine intake and thyroid status in preterm infants
Insights
Increased iodine in preterm infant formula did not improve thyroid hormone levels in preterm babies. This study suggests current iodine levels are adequate, questioning the need for formula supplementation.
Area of Science:
- Neonatal nutrition
- Endocrinology
- Pediatric research
Background:
- Low thyroid hormone levels in preterm infants are linked to poor neurodevelopmental outcomes.
- Inadequate iodine intake from formula may contribute to low thyroid hormone levels in preterm infants.
Purpose of the Study:
- To determine if increased iodine intake via supplemented preterm formula improves thyroid hormone levels in preterm infants.
- To assess the potential impact on neurodevelopmental status in a subsequent study.
Main Methods:
- A randomized controlled trial involving 121 preterm infants.
- Comparison of standard (68 microg/l) versus increased (272 microg/l) iodine content in preterm formula.
- Monitoring of thyroid hormone levels up to 41 weeks post-conception.
Main Results:
- No significant difference in thyroid hormone levels was observed between the standard and increased iodine groups.
- The intervention did not demonstrate a measurable effect on thyroid hormone status in preterm infants.
Conclusions:
- The study does not support calls for increased iodine content in preterm infant formulas.
- Current iodine levels in standard preterm formulas appear sufficient based on this research.
Background:
Low levels of circulating thyroid hormones have been associated with poorer general and neurodevelopmental outcome in preterm babies and it has been speculated that the association is causal. Low levels of circulating thyroid hormone have been reported after inadequate intake of iodine in preterm infants being fed milk formula.
Aim:
To investigate whether increased iodine intake from supplemented preterm formula would improve thyroid hormone levels in preterm babies (this study) and hence improve neurodevelopmental status (planned subsequent study).
Method:
A total of 121 preterm infants were entered into a randomised controlled trial of standard (68 microg/l) versus increased (272 microg/l) iodine in preterm formula.
Results:
The two groups were comparable at recruitment. No evidence of an effect of the intervention on thyroid hormone levels was seen up to 41 weeks after conception.
Conclusion:
Calls for increased iodine content of preterm infant formulas are not justified by this study.
