Prevalence of iron deficiency in rural pre-school children in Northern Ireland.

Screening for iron deficiency was offered to 485 pre-school children in one practice. A questionnaire asking for details of the child's birth, diet, medical history and social status was sent to all the families of these children. Three hundred and eleven children (64% of the total) had blood samples taken for haemoglobin concentration, mean corpuscular volume and serum ferritin levels. Fifty four of the children (17%) were iron deficient (serum ferritin less than 10 micrograms l-1 or mean corpuscular volume less than 75 fl), while 10 (3%) had iron deficiency anaemia (haemoglobin level less than 10.5 g dl-1). The prevalence of iron deficiency and iron deficiency anaemia were not significantly associated with any social class. However, there was a higher prevalence among social class 3 children than children from other social classes, 29% of them having covert iron deficiency, while 6% were frankly anaemic. As there are no ethnic minorities in the practice, dietary inadequacy was likely to be the main cause of iron deficiency. After receiving iron supplements for up to three months, all the children who were iron deficient or anaemic and attended for follow up had normalized blood values. In view of the high prevalence of iron deficiency throughout the social classes, and its association with developmental delay and behavioural disorders, screening will be offered to all children when they attend for measles, mumps and rubella immunization, and those who do not attend will be followed up.