Hair trace elements and mental retardation among children

The calcium, magnesium, zinc, iron, and copper content found in scalp hair of 40 children with mental retardation were compared with 37 healthy normal children who were between the ages of 4 and 14 yr. The hair of children with mental retardation showed significantly lower levels of iron, copper, and magnesium (p less than .001) and higher levels of calcium (p less than .001). The zinc content did not differ between the two groups. The differences in levels of hair trace elements between normal children and those with mental retardation could be of particular interest in the investigation of the cause of mental retardation among children.