Haemoglobin, ferritin, and iron intakes in British children aged 12–14 years: a preliminary investigation

Abstract

The purpose of the study was to assess the prevalence of Fe deficiency and Fe-deficiency anaemia in a group of apparently healthy adolescents, and to assess the value of a food frequency and amount questionnaire as a screening tool to identify children at risk of Fe deficiency. White schoolchildren (399) aged 12–14 years living in a Southwest London suburb completed a food frequency and amount questionnaire to assess usual Fe and vitamin C intake, and provided a thumb-prick blood sample for analysis of haemoglobin (Hb), packed cell volume (PCV), and serum ferritin (SF). Children were classified as ‘anaemic’ if Hb was below the Dallman 3rd percentile (girls: < 120 g/l; boys: < 122, < 124 and < 126 g/l at ages 12, 13 and 14 years respectively); and ‘low’ or ‘borderline’ in Fe stores if SF was < 12 μg/l, or between 12 and 20 μg/l respectively. Of the boys and girls 3·5 and 10·5% respectively were anaemic; 1% of boys and 4% of girls had low ferritin values, and 14% of boys and 16% of girls were borderline. Fe intakes were significantly higher in boys than in girls (12·3 v. 9·6 mg/d, P < 0·001). Prevalence of anaemia was 14·5% in the group with both low Fe intakes (< lower reference nutrient intake) and low vitamin C intakes (< median), compared with 2·3% in the group with both high Fe intakes (> reference nutrient intake) and high vitamin C intakes (> median). Anaemia was three times more common in vegetarians than omnivores (25 v. 9%), and in girls who had tried to lose weight in the last year compared with those who had not (23 v. 7%). The questionnaire did not prove satisfactory as a screening tool for risk of Fe deficiency. The higher-than-expected prevalence of Fe deficiency in apparently healthy white girls suggests that other groups should also be investigated.