REVIEW ERS ' CONCLUSIONS Despite most of the included studies being of low quality , the results suggest that iodine supplementation , especially iodised oil , is an effective means of decreasing goitre rates and improving iodine status in children .
Indications of positive effects on physical and mental development and mortality were seen , although results were not always significant .
Adverse effects were generally minor and transient .
BACKGROUND Iodine deficiency is the main cause of potentially preventable mental retardation in childhood , as well as causing goitre and hypothyroidism in people of all ages .
It is still prevalent in large parts of the world .
OBJECTIVES To assess the effects of iodine supplementation overall , and of different forms and dosages of iodine supplementation separately , in the prevention of iodine deficiency disorders in children .
Effect of iron-, iodine-, and beta-carotene-fortified biscuits on the micronutrient status of primary school children: a randomized controlled trial.
BACKGROUND Deficiencies of iron , iodine , and vitamin A are prevalent worldwide and can affect the mental development and learning ability of schoolchildren . OBJECTIVE The aim of this study was to determine the effect of micronutrient-fortified biscuits on the micronutrient status of primary school children . DESIGN Micronutrient status was assessed in 115 children aged 6 - 11 y before and after consumption of biscuits ( fortified with iron , iodine , and beta-carotene ) for 43 wk over a 12-mo period and was compared with that in a control group ( n = 113 ) who consumed nonfortified biscuits .  Cognitive function , growth , and morbidity were assessed as secondary outcomes . RESULTS There was a significant between-group treatment effect on serum retinol , serum ferritin , serum iron , transferrin saturation , and urinary iodine ( P < 0.0001 ) and in hemoglobin and hematocrit ( P < 0.05 ) . The prevalence of low serum retinol concentrations ( < 0.70 micromol/L ) decreased from 39.1 % to 12.2 % , of low serum ferritin concentrations ( < 20 microg/L ) from 27.8 % to 13.9 % , of anemia ( hemoglobin < 120 g/L ) from 29.6 % to 15.6 % , and of low urinary iodine concentrations ( < 100 microg/L ) from 97.5 % to 5.4 % . There was a significant between-group treatment effect ( P < 0.05 ) in cognitive function with the digit span forward task ( short-term memory ) . Fewer school days were missed in the intervention than in the control group because of respiratory- ( P = 0.097 ) and diarrhea-related ( P = 0.013 ) illnesses . The intervention had no effect on anthropometric status [ corrected ] . CONCLUSIONS Fortified biscuits result ed in a significant improvement in the micronutrient status of primary school children from a poor rural community and also appeared to have a favorable effect on morbidity and cognitive function [ corrected ]
REVIEW ERS ' CONCLUSIONS Despite most of the included studies being of low quality , the results suggest that iodine supplementation , especially iodised oil , is an effective means of decreasing goitre rates and improving iodine status in children .
Indications of positive effects on physical and mental development and mortality were seen , although results were not always significant .
Adverse effects were generally minor and transient .
BACKGROUND Iodine deficiency is the main cause of potentially preventable mental retardation in childhood , as well as causing goitre and hypothyroidism in people of all ages .
It is still prevalent in large parts of the world .
OBJECTIVES To assess the effects of iodine supplementation overall , and of different forms and dosages of iodine supplementation separately , in the prevention of iodine deficiency disorders in children .