Iron status in 2-year-old Icelandic children and associations with dietary intake and growth

OBJECTIVE: To investigate the effects of food and nutrient intake at 2 y and growth from birth on iron status at 2 y in a population with high birth weight.

DESIGN: In a cross-sectional study, children's food consumption and body size measurements were recorded and blood samples taken. Weighed 3-day food records were used to analyse food and nutrient intake.

SETTING: Children were recruited from across Iceland from the Icelandic National Registry by the University of Iceland, Computing Services. The children in the sample were born over a 1-y period.

SUBJECTS: Parents of randomly selected 2-year-old children (n=130) were contacted, and 72% (n=94) participated. Blood samples were analysed in 76% (n=71) of participating children.

RESULTS: In total, 9% of the children were iron-deficient (serum ferritin (SF)<12 microg/l and mean corpuscular volume (MCV) <74 fl) and 1.4% were also anaemic (Hb<105 g/l), while 27% of children were iron-depleted (SF<12 microg/l). Iron status indices were negatively associated with cow's milk consumption. Half of children consuming>500 g cow's milk/day (n=10) were iron-deficient, while one child in 58 consuming<500 g cow's milk/day had iron deficiency (P<0.001). In multiple regression analyses, also biscuits and crackers consumption was positively associated with MCV. Weight gain from birth to 2 y was negatively associated with SF (adjusted R(2)=0.15; P=0.002; n=58). Iron-depleted children were heavier than children not iron-depleted (14.7+/-1.3 vs 13.8+/-1.7 kg; P=0.043), had higher BMI (17.7+/-1.5 vs 16.7+/-1.4 kg/m(2); P=0.028) and gained more weight from birth (11.2+/-1.3 vs. 10.0+/-1.6 kg; P=0.011).

CONCLUSIONS: The results suggest that cow's milk consumption above 500 g/day should be avoided at the age of 2 y for better iron status. Iron depletion at 2 y is associated with faster growth from birth.