Vol. 12, No. 1, 2006 Page 3

Iron: Too little, too much a risk for behavioral problems?

Iron deficiency is associated with attention deficit hyperactivity disorder (ADHD), with a study last year by Eric Konofal and colleagues revealing that one-third of children with ADHD but only 3% of non-ADHD children have extremely low iron levels (see related article, Crime Times, 2005, Vol. 11, No. 1, Page 4). A new study by the same researchers indicates that correcting iron deficiency can dramatically reduce ADHD symptoms—but another research group's findings suggest that too much iron during prenatal development can lead to behavior problems.

In the new study, Konofal and colleagues conducted a single-case experiment to see if restoring iron levels to normal could lead to a reversal of ADHD symptoms. Their subject, a three-year-old boy, exhibited marked impulsivity, inattention, hyperactivity, and sleep problems. Testing revealed low iron stores, although the boy was not anemic.

The researchers began supplementing the boy with 80 mg of ferrous sulfate per day, and after four months of treatment, his iron levels normalized. At that point, parents and teachers reported only mild behavioral improvement, although the boy's sleep patterns did improve markedly. However, after eight months of iron treatment, the boy's parents described him as "transformed," and teachers reported that he was far more organized and attentive, much better at relating to other children, and less forgetful and impulsive. On the Conners' Parent and Teacher Rating Scales for hyperactivity, his scores dropped significantly, from 30 and 32 respectively before treatment to 19 and 13 afterward.

Noting that a 1997 study (Sever et al.) reported only modest improvements in boys with ADHD receiving iron supplementation, Konofal and colleagues point out that none of the boys in the earlier study were actually iron-deficient and that treatment continued for only 30 days compared to eight months in the current study. "In animal models," Konofal et al. say, "it has been reported that iron supplementation in iron deficient rats restored blood hemoglobin levels faster than brain iron levels; improvement in learning deficits lags behind blood hemoglobin by at least two months."

While iron treatment appears to be remarkably beneficial for a number of ADHD children, a research group in Australia is reporting that non- iron-deficient mothers who take iron during pregnancy may be putting their children at risk for future behavior problems.

S. J. Zhou and colleagues initially set out to investigate the possibility that children whose mothers took iron supplements might have higher IQs or exhibit better behavior than other children. Their investigation was based on the fact that offspring of iron-deficient rats consistently show behavioral deficits.

However, when the researchers evaluated 300 children of non-iron- deficient mothers, half of whom took iron during pregnancy, they discovered that there were no IQ differences but that a higher percentage of children of mothers in the iron group exhibited hyperactivity and other behavior problems. The findings appear to suggest that iron supplementation during pregnancy is appropriate only for mothers who are iron-deficient.


"Effectiveness of iron supplementation in a young child with attention- deficit/hyperactivity disorder," Eric Konofal, Samuele Cortese, Michel Lecendreux, Isabelle Arnulf, and Marie Christine Mouren, Pediatrics, Vol. 116, No. 5, November 2005, e732-4 (epub ahead of print publication). Address: Eric Konofal, Service de Psychopathologie de l' Enfant et de l' Adolescent, 48 Boulevard Serurier, 75019 Paris, France, eric.konofal@rdb.ap-hop-paris.fr.


"Behavioral effects of prenatal iron supplementation in children: long term follow up of a randomized controlled trial," S. J. Zhou, M. Makrides and R. A. Gibson, Asia Pacific Journal of Clinical Nutrition, Vol. 14 (Supplement), November 2005, S46. Address: Maria Makrides, Child Health Research Institute, 72 King William Road, North Adelaide, South Australia 5006, maria.makrides@cywhs.sa.gov.au.

--see also--

"Iron 'risk' warning for mothers-to-be," Louise Gray, The Scotsman, October 27, 2005.

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