Washington: Even a mild iodine deficiency
can affect children`s intelligence -- though this could easily
be solved with diet, says a new study.
An international team, led by Otago University, has
carried out the study and found that mild iodine deficiency
may prevent children from reaching their full intellectual
potential, `American Journal of Clinical Nutrition` reported.
Lead researcher Dr Sheila Skeaff said while moderate
to severe deficiency of this trace element has well-known and
sometimes disastrous effects on children`s brain development,
it had previously been thought that being only mildly iodine
deficient had no significant cognitive consequences.
"Our findings challenge this assumption. They also
show that the new era of mandatory fortification of most bread
with iodised salt is a good move, which may reap even greater
benefits than initially thought," she said.
In their study, the undertook a 28-week-long trial
involving 184 Dunedin children aged between 10 and 13. The
kids, who were found to be mildly iodine deficient at the
outset, were randomly assigned to groups which either received
daily iodine tablets or a placebo.
At the beginning and end of the trial, both groups
underwent cognitive testing using four subtests from WISC-IV,
which is a standard intelligence test used for children.
By the trial`s end, the researchers found the
kids taking the iodine supplement had achieved adequate iodine
status, while the placebo group remained mildly deficient.
"In the initial round of cognitive testing, there were
no significant differences between the two groups` scores.
When tested again at the end of the trial, in two subtests
measuring perceptual reasoning, the iodine group showed a
significantly improved performance relative to the placebo
group," Dr Skeaff said.
"While children eating fortified bread should benefit
through improving their iodine status, those who do not eat it
should be taking steps to increase their iodine intakes in
"Although fish and seafood are rich sources of iodine,
most children eat small quantities of these foods. If salt is
used in the home at the table or cooking it should be iodised.
"Parents should also consider giving children who do
not eat commercial breads an iodine-containing multimineral
supplement. However, it is important to note that there is no
evidence that large doses of iodine will lead to large
cognitive gains," she said.