It should be noted that the use of fluoride supplements in areas with fluoridated drinking water, or in any circumstance were the child has other sources of fluoride exposure, might increase the risk of enamel fluorosis, changes in the appearance of teeth. (28)
Iodine deficiency and children:
Iodine requirements during pregnancy may affect children: Iodine deficiency reduced intelligence in infants and children and thus is of critical importance during pregnancy. While the maximum safe dose is no more than 1 mg, this upper limit might be increased given than the Japanese consume 25 times the median iodine consumption in the US, without adverse effects. More insight might be gained from studies using 3 mg- 6mg iodine which are used to treat fibrocystic breast disease. (29)