Some research has shown an association between ADHD and iron deficiency although the link isn't clearly understood. Children with ADHD may have lower levels of iron even though research is mixed as to whether supplementing iron significantly improves symptoms.
Children with ADHD May Have Lower Levels of Iron
A study completed in 2004 showed that children with ADHD were more likely to have lower levels of iron with those with the most severe iron deficiencies having more severe symptoms of ADHD. In this study researchers looked at 80 children - 53 with ADHD and 27 without ADHD but who had a mild learning disability. Eighty-four percent of the children with ADHD had low levels of iron as compared to only 18 percent of those without ADHD. The researchers noted that none of the children in the study had malnutrition.
The scientists didn't believe that iron supplementation should be an immediate treatment for children with ADHD, however, they did recommend that children with ADHD be tested for iron deficiency and treated as needed.
Symptoms of Iron Deficiency
Slower mental development or mental confusion, irritability, cognitive impairment and learning disability have all been linked to iron deficiencies. Common symptoms of anemia include:
- Shortness of breath
- Rapid heartbeat
- Ringing in the ears
- Pale skin
Some complications of iron deficiency include:
- Delay of normal infant motor function
- Delay of thinking and processing skills
- Problems with memory and other mental function in teens
- Behavior problems
Some people with iron deficiency may also develop restless leg syndrome, which often interferes with sleep.
While the study from 2004 showed the majority of children with ADHD had low iron levels, not all studies came up with the same results. A review of all studies relating to ADHD and iron levels in 2012 found mixed results. Some studies showed clear correlations, including improvements in the Conner's Parent Rating when children were given iron supplements. One study showed increased levels of iron. But there were also many studies that did not indicate any correlation between ADHD and iron levels.
Scientists point to several possible reasons for the mixed results. Children with ADHD who are currently taking stimulant medications may have a decreased appetite and therefore not be eating a balanced diet. Another possible explanation may be the different ways of measuring iron levels used in the various studies.
Another study showed that iron deficiency may decrease the effectiveness of stimulant medications, causing symptoms to appear worse.
Is Iron Supplementation the Answer?
A few studies have shown that iron supplementation can help to improve symptoms of ADHD but these results are mixed as well. A study completed in 2008 showed "Iron supplementation appeared to improve ADHD symptoms in children with low iron levels."  But, even that study showed some discrepancies, with little change or improvement in the Conner's Parents Rating Scale and Conner's Teacher Rating Scale, even though overall symptoms seemed to decrease.
Experts caution parents not to buy iron supplements for their children. Instead, ask your doctor to test iron levels to determine if they are low. Supplementing with iron can be dangerous if your child has normal iron levels - too much iron can lead to liver and heart problems.
"Effectiveness of Iron Supplementation in a Young Child with Attention Deficit/Hyperactivity Disorder," 2005, Nov 1, Eric Konofal et al, Pediatrics
 "Effects of Iron Supplementation of Attention Deficit Hyperactivity Disorder in Children," 2008, Eric Konofal et al, Pediatric Neurology
"Iron and Attention Deficit/Hyperactivity Disorder: What Is the Empirical Evidence So Far? A Systematic Review of the Literature," 2012, Oct., S. Cortese, M Angriman, M. Lecendreus, E. Konofal, Expert Rev Neurotherapy
"Iron and Iron Deficiency," Reviewed 2011, Feb. 23, Staff Writer, U.S. Centers for Disease Control and Prevention
"What Are the Signs and Symptoms of Iron-Deficiency Anemia?" 2011, April 1, Staff Writer, National Institutes of Health