My six-year-old son Casey has always been a busy child, and he barely touches down at the table to eat his meals. I take pride in being a parent who is non-alarmist, and IÂ’ve never really been concerned about his choosy eating until this year. I put three nutritious meals in front of him each day, and I figured he would eat if he needed to eat.
My pediatrician once told me, Â“Kids donÂ’t always eat well every day, but if you average out what they eat in the course of a week, they usually get what they need.Â”
My husband also pointed out, Â“He poops enough, so he must be eating enough.Â” This seemed so rational, I found it reassuring.
Casey certainly has always taken in adequate calories. He is a bundle of energy, usually climbing across our furniture or racing around our home. What calories he misses at mealtime, he has always made up for by drinking milk. He loves milk, and always has. It takes my constant attention to make sure that we donÂ’t run out of milk in our houseÂ—left to his own devices, Casey could go through a half gallon in a day.
But this year Casey has had trouble. In the second half of his kindergarten year, his learning curve flattened and he stopped showing interest in learning how to read. He stopped listening well at school, sometimes gazing off in a trance, or fidgeting badly during quiet times, incapable of paying attention. At other times he was dramatically hyperactive, disrupting the class or racing up and down trees and around his school. He was impulsive at homeÂ—hitting his baby brother over the head after only minor provocations.
Our Casey had all the signs of attention deficit hyperactivity disorder (ADHD), a problem that typically begins at his age or shortly afterwards. ADHD affects boys far more often than girls. The three behavior patterns that occur in ADHD are inattention, impulsive behavior, and hyperactivity. At the request of our pediatrician, I asked his teachers to fill out a questionnaire about Casey. The questionnaire was the ConnorsÂ’ Rating Scale, a series of questions that is used to give a child a score that describes his behavior. If the score is very high, it is likely the child has ADHD.
We brought Casey to a psychologist to learn the results of the test. Â“I have never seen a rating scale like CaseyÂ’s from his teachers,Â” he said. Â“He scored at the most extreme level for almost every question.Â”
I reflected about his abrupt change this year. He seemed to be regressing in many waysÂ—he began sleeping in our bed again, he began to chew on Kleenex tissues instead of blowing his nose with them, and he chewed on small parts from his toys, like the tires from his Lego cars. He also began to chew the sleeves and the collars of his shirts, soaking his front with saliva and shredding his shirts as he chewed. This chewing was not a typical part of ADHD. In fact, it was bizarre.
As I thought about Casey and his incessant chewing, I had an important idea.
The bodyÂ’s quest for iron
As a primary care doctor, I take care of adults. When my patients have low iron levels, they have telltale signs. They lack energy, they get tired more easily with exercise, they sometimes complain of headaches, and they may be pale. In addition to these symptoms, iron deficiency causes curious cravingsÂ—an urgent need to chew ice, for example. Ice doesnÂ’t contain iron, so ice crunching doesnÂ’t help the problem. Yet as strange as it may seem, ice crunching is a fairly useful clue to doctors that the iron might be low.
Children donÂ’t always pay attention to what is and is not edible when they put things into their mouths.Â Some children develop cravings to chew on many things when they need more ironÂ— paper, paint chips, clay, dirt, you name it. This eating of non-nutritive items is called Â“pica.Â” Pica is not always caused by iron deficiency, but low iron frequently is the cause.
Could CaseyÂ’s shirt-chewing and toy-chewing come from iron deficiency? As soon as I asked myself this question, I knew it was likely.
Most adults with low iron get that way by losing bloodÂ—for example, from intestinal bleeding or, for women, from heavy periods. Most adult Americans get plenty of iron in their diets. But anyone who binges on a favorite food can eat a less varied diet than is needed. This is true for an alcoholic, who gets calories from beer or liquor and who has inadequate hunger for nutritious food. This is also true for children with a favorite food, particularly children who drink too much milk. Thirteen percent of young grade school children are iron deficient. Casey was one of these kids.
Beyond anemia: IronÂ’s subtle effects in the brain
Most people understand that low iron leads to anemia and feelings of fatigue. Most people donÂ’t know about the more curious troubles that low iron can provoke.
For instance, restless legs syndromeÂ—an urge to move the legs when you are in bed at nightÂ—can be caused by low iron. Restlessness of the legs may be caused by a change in the brain hormone Â“dopamine.Â” Â Â A change in dopamine can be related to your iron level. Iron has to be available in adequate amounts for your brain to keep its dopamine at a normal level.
ADHD is not perfectly understood, but it occurs when there is a change in brain chemistry. Medicines like Ritalin that alter brain chemistry can improve ADHD symptoms. One of the hormone shifts that can trigger ADHD is, in fact, a change in the dopamine level.
Can low iron cause symptoms that mimic ADHD? Yes, in some cases it can. On average, children with ADHD have lower iron levels than is normal. Some children with ADHD behaviors have strikingly low iron levels. When these children get their iron levels to normal by taking iron supplements, they can have a slow but steady improvement in their attention and hyperactivity.
CaseyÂ’s iron deficiency was obvious once we had his blood tested. His blood count (hematocrit) was seven points lower than what is average for his age, and his iron test was very low. We have changed our dinner menu to bring on the red meat, and he is taking iron supplements twice a day. Slowly, slowly, but surely, Casey is regaining his listening and his self-control.
The connection between iron and ADHD has only been recognized by doctors during the last five to ten years. Only a few small studies have been published to explore the connection. Feeling hopeful, some doctors have tried treating children who had ADHD with iron supplements even when the children had normal iron levels. But this didnÂ’t work--children who start out with normal iron levels donÂ’t appear to have any change in their behavior when iron is replaced. Reviewing these results, experts agree that children who donÂ’t need extra iron should not be given supplements. When it is overdone, iron supplementation can actually be dangerous.
So far, testing iron has not become a standard part of the medical evaluation for children with ADHD behavior. For a few children with ADHD, iron is the issue. If your child has behavior like ADHD, I recommend asking your doctor to arrange a blood test that can check for iron deficiency. Even in a home where food is abundant, it is easy enough for a child to get too little iron.
Do you know a child with ADHD? If so, do you know whether iron has been tested? Do you have good advice for parents whose children are picky eaters?
Mary Pickett, M.D., is an Associate Professor of Medicine at Oregon Health & Science University where she is a primary care doctor for adults. Her field is Internal Medicine. She is also a Lecturer for Harvard Medical School and a Senior Medical Editor for Harvard Health Publications.------------------------------------------------------------------------------------------------
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