Even in developed western countries such as Australia, the incidence of iron deficiency is as high as 20 per cent in young children and adolescents. Lack of this important mineral in childhood differs from the conditions in adults. In kids, the most likely cause of deficiency is a lack of iron in the diet coupled with increase in the amount of iron needed for growth. While profound deficiencies might show up as anaemia, in many children the only symptoms may be irritability, difficulty in concentrating, lethargy and minor behavioural changes that are often ascribed to tiredness or just bad manners. There is also evidence that the intellectual and psychomotor impairment caused by iron deficiency may not be always completely reversible when the iron status is corrected.
Iron deficiency can reduce immune function and cause a loss of appetite.
But unfortunately, a large proportion of children who are iron deficient have no symptoms at all. In older children and adolescents, difficulty in concentrating is a common symptom of such deficiency. Iron carries oxygen around the body and caters a large portion of its supply to the brain, which has a huge demand. Sufficient iron is essential for brain function, especially attention and memory, and iron-deficiency can affect a child's ability to concentrate. One study on 213 male and female adolescents found higher academic achievement scores in those with better iron status.