Iron intakes and status of 2-year-old children in the Cork BASELINE Birth Cohort Study

Abstract

Young children are at risk of iron deficiency and subsequent anaemia, resulting in long-term consequences for cognitive, motor and behavioural development. This study aimed to describe the iron intakes, status and determinants of status in 2-year-old children. Data were collected prospectively in the mother-child Cork BASELINE Birth Cohort Study from 15 weeks' gestation throughout early childhood. At the 24-month assessment, serum ferritin, haemoglobin and mean corpuscular volume were measured, and food/nutrient intake data were collected using a 2-day weighed food diary. Iron status was assessed in 729 children (median [IQR] age: 2.1 [2.1, 2.2] years) and 468 completed a food diary. From the food diary, mean (SD) iron intakes were 6.8 (2.6) mg/day and 30% had intakes < UK Estimated Average Requirement (5.3 mg/day). Using WHO definitions, iron deficiency was observed in 4.6% (n = 31) and iron deficiency anaemia in five children (1.0%). Following an iron series workup, five more children were diagnosed with iron deficiency anaemia. Twenty-one per cent had ferritin concentrations <15 µg/L. Inadequate iron intakes (OR [95% CI]: 1.94 [1.09, 3.48]) and unmodified cows' milk intakes ≥ 400 mL/day (1.95 [1.07, 3.56]) increased the risk of low iron status. Iron-fortified formula consumption was associated with decreased risk (0.21 [0.11, 0.41] P < 0.05). In this, the largest study in toddlers in Europe, a lower prevalence of low iron status was observed than in previous reports. Compliance with dietary recommendations to limit cows' milk intakes in young children and consumption of iron-fortified products appears to have contributed to improved iron status at two years.

Keywords: anaemia; birth cohort; cows' milk consumption; food fortification; iron deficiency; iron intakes.

Figure 1

(a) Distributions of mean daily iron intakes (mg/day) among food group consumers. Total population (●, n = 461), iron‐fortified breakfast cereal only (excluding all formula) consumers (♦, n = 322), formula consumers (▲, n = 95) and base diet (excluding all iron‐fortified products) consumers (■, n = 44). Iron supplement users (n = 7) excluded. Dashed line indicates UK EAR (5.3 mg/day) (b) Distributions of serum ferritin concentrations (μg/L) among food group consumers. Total population (●, n = 257), iron‐fortified breakfast cereal only (excluding all formula) consumers (♦, n = 173), formula consumers (▲, n = 51) and base diet (excluding all iron‐fortified products) consumers (■, n = 33). Iron supplement users (n = 6) excluded. Serum ferritin cut‐offs of 12 and 15 μg/L are indicated on the chart by the dashed lines.