Thus , regardless of study design , iodine deficiency had a substantial impact on mental development .
Several review s and meta-analyses have examined the effects of iodine on mental development .
None focused on young children , so they were incomplete in summarizing the effects on this important age group .
The current systematic review therefore examined the relationship between iodine and mental development of children 5 years old and under .
The effects of oral iodized oil on intelligence, thyroid status, and somatic growth in school-age children from an area of endemic goiter.
One hundred goitrous school children received 475 mg iodized oil by mouth , while 100 controls received mineral oil , on a double-blind basis . On follow-up 22 months later the urinary iodine had increased and goiter size had decreased in both groups , more strikingly in the iodine-treated children . There were no consistent differences between the two treatment groups in rate of somatic growth or performance on the Stanford-Binet and Bender tests . Because of the complexities introduced by increases in urinary iodine in the controls , we compared goiter reduction with improvement in IQ score in all children , regardless of group , and found a significant relationship ( p = 0.014 ) , particularly in girls ( p = 0.029 ) . We conclude that oral iodized oil is an attractive alternative to its injection but we recommend an approximate doubling of the dose used here for more effective control . Also , while our data are not conclusive , they support the possibility that correction of iodine deficiency may improve mental performance in school age children , particularly girls
Thus , regardless of study design , iodine deficiency had a substantial impact on mental development .
Several review s and meta-analyses have examined the effects of iodine on mental development .
None focused on young children , so they were incomplete in summarizing the effects on this important age group .
The current systematic review therefore examined the relationship between iodine and mental development of children 5 years old and under .