In anaemic groups supplementation improved intelligence quotient ( IQ ) by 2.5 points ( 95 % CI 1.24 to 3.76 ) , but had no effect on non-anaemic participants , or on memory , psychomotor skills or scholastic achievement .
Background In observational studies anaemia and iron deficiency are associated with cognitive deficits , suggesting that iron supplementation may improve cognitive function .
However , due to the potential for confounding by socio-economic status in observational studies , this needs to be verified in data from r and omised controlled trials ( RCTs ) .
Aim To assess whether iron supplementation improved cognitive domains : concentration , intelligence , memory , psychomotor skills and scholastic achievement .
Once-weekly and 5-days a week iron supplementation differentially affect cognitive function but not school performance in Thai children.
Many studies have reported comparable hemoglobin response in subjects given intermittent and daily iron supplements .  However , the effect of intermittent iron supplementation on impaired cognitive function , one of the serious consequences of iron deficiency among children , has not been studied . We investigated the effects of 1 d/wk ( weekly ) and 5 d/wk ( daily ) iron supplementation on changes in results of intelligence quotient ( IQ ) , Thai language , and mathematics tests among Thai primary schoolchildren . A double-blind , r and omized , placebo-controlled trial was conducted . Primary schoolchildren ( n = 397 ) were r and omly assigned to receive iron supplements daily or weekly or placebo . Ferrous sulfate ( 300 mg ) or placebo tablets were given under direct observation by the research er for 16 wk . Changes in IQ , and Thai language and mathematics scores were then compared . The increases in hemoglobin concentration were comparable in the weekly and daily iron supplementation groups but serum ferritin increased more in the children supplemented daily . Children receiving daily iron supplements , however , had a significantly lower increase in IQ ( 3 + /- 12 points ) than those receiving the supplement weekly ( 6 + /- 12 points ) or placebo ( 6 + /- 12 points ) , whereas the last-mentioned two groups did not differ . Z-scores of Thai language and mathematics test results did not differ among the groups . We conclude that weekly iron supplementation is the regimen of choice in this study community
In anaemic groups supplementation improved intelligence quotient ( IQ ) by 2.5 points ( 95 % CI 1.24 to 3.76 ) , but had no effect on non-anaemic participants , or on memory , psychomotor skills or scholastic achievement .
Background In observational studies anaemia and iron deficiency are associated with cognitive deficits , suggesting that iron supplementation may improve cognitive function .
However , due to the potential for confounding by socio-economic status in observational studies , this needs to be verified in data from r and omised controlled trials ( RCTs ) .
Aim To assess whether iron supplementation improved cognitive domains : concentration , intelligence , memory , psychomotor skills and scholastic achievement .