A longitudinal study of iron status in children at 12, 24 and 36 months

Objectives: To assess iron status in a sample of clinically well, Caucasian children and explore the complex factors which contribute to iron deficiency during infancy. Design: Infants recruited at birth and followed longitudinally at 1,2,3,4,5,6,9,1 2, 24 and 36 months; feeding practices and socioeconomic data recorded. Iron status assessed using venous blood at 12, 24 and 36 months. Setting: Baseline data recorded in the maternity unit. Follow-up visits took place in the infants' homes and blood sampling in a paediatric hospital. Subjects: Subjects comprised a mixed socioeconomic group of healthy children (n = 121). Blood samples taken from 85, 72 and 67% at 12, 24 and 36 months, respectively. Results: Prevalence of anaemia (Hb < 110 g l(-1)) in the longitudinal sample (n = 76) increased from 2.6% at age 12 months to 9.2% at 24 months, and at age 36 months (n = 70) was 8%. The most significant finding was that at age 12 months, cows' milk consumption was negatively associated with iron status. Other variables also had an influence. At both 24 and 36 months the most significant predictor of iron status was earlier iron status. Conclusions: Infants born to anaemic mothers or mothers who smoke and infants who consume cows' milk during infancy are at increased risk of developing anaemia. Breast milk is the ideal, but for the infant who is not breast fed an iron fortified formula should be used. Advice to mothers should focus on the importance of introducing nutrient dense complementary foods, such as meat, which contains readily absorbable iron.