About 8% of children, ages 4 years and under, are deficient in iron. Between the ages of 5 and 12, the percentage rises to 13%, and then settles back to 8% in people above the age of 15. Anemia is the best-known repercussion of iron deficiency. However, even minor deficiencies in iron may weaken the immune system, affect the thyroid, and impair general physical performance. Iron deficiency has also been implicated in a number of psychiatric and neurological conditions, including learning disabilities and ADHD.

Iron is a co-enzyme in the anabolism of catecholamines. That means it is essential for the creation of certain neurotransmitters. It helps to regulate the activity of the neurotransmitter dopamine, which probably accounts for the association of iron deficiency with neurological problems. It makes sense that supplementing ADHD children, who have some level of iron deficiency, might have some effect on their ADHD. However, what makes sense in theory, does not always work in practice. Unfortunately, there have been very few studies done testing the effects of iron supplementation on ADHD.

One study, done in Israel, evaluated 14 ADHD boys for the effect of short-term iron administration on behavior. Each boy received iron daily for 30 days. Both parents and teachers assessed the behavior of the children. The parents found significant improvement in the behavior of the children. However, the teachers noticed no improvement.

In a second study, 33 iron-deficient, but otherwise normal, children were given an iron supplement. The children became less hyperactive. This study suggests that iron deficiency may cause hyperactive behavior in some children and that hyperactive behavior is reversible when the deficiency is treated.

A third study tested the affects of iron supplementation on a group of teen-aged high school girls who were determined to be iron deficient. At the end of the 8-week study, the researchers found that girls who received iron supplementation performed better on verbal learning and memory tests than those who did not.

This is about all the evidence we have. It