A LONGITUDINAL-STUDY OF IRON STATUS IN HEALTHY DANISH INFANTS - EFFECTS OF EARLY IRON STATUS, GROWTH VELOCITY AND DIETARY FACTORS

In a cohort of term infants (n = 91), followed from birth to 12 months , iron intake was examined by 24-h food records, and iron status by bl ood samples (haemoglobin (Hb), mean corpuscular volume (MCV), serum va lues for iron, ferritin and transferrin, and erytkrocyte protoporphyri n) at 2, 6 and 9 months. At 9 months of age, 5% had anaemia (Hb < 105 g/l), but none had developed iron deficiency according to strict defin itions used in this study (serum ferritin < 13 mu g/l and transferrin saturation < 10%). Infants with high serum ferritin, serum transferrin and erythrocyte protoporphyrin values at one blood sampling also had high values at the following sample (tracking, r = 0.45-0.80), suggest ing that iron stores at delivery are an important determinant of iron stores during late infancy. Factors related to changes in serum ferrit in were investigated by multiple linear regression. From 2 to 6 months , serum ferritin was negatively associated with knee-heel growth veloc ity (p = 0.006) and positively with intake of infant formula (p = 0.04 ). From 6 to 9 months it was negatively associated with intake of brea d (p = 0.001), and there was a trend for a positive association with i ntake of meat (p = 0.07) and fish (p = 0.08) and for a negative associ ation with intake of cow's milk (p = 0.07). In conclusion, those with a high growth velocity and a dietary pattern with a high intake of bre ad and a low intake of meat and fish had lower ferritin values and the reby an increased risk of depleting their iron stores later during inf ancy.