IRON AND ZINC CONCENTRATIONS
IN HUMAN MILK DURING LACTATION: A 4-MONTH LONGITUDINAL STUDY
Ozkan TB *, Durmaz NG*, Ozeke T*, Durmaz O*, Coker C**
* Department of Pediatric Gastroenterology, Uludag University,
Medical Faculty, Bursa, Turkey
** Department of Biochemistry, 9 Eylul University, Medical Faculty,
Izmir, Turkey
Aim: The concentrations of most minerals in the breast milk
remain fairly constant throughout the course of lactation. The exceptions
are zinc (Zn), copper (Cu) and iron (Fe). In this study, the contents of Fe
and Zn were determined in human milk samples from 27 Turkish women
longitudinaly for four months of lactation.
Methods: These mother's infants were grouped according to
breast-feeding (group I=16) or mixed feeding (group II=11: breast milk and
formula). The concentrations of Zn and Fe in maternal serum and breast milk
at 0,1 and 4 months of lactation were compared with each other. These
parameters were also correlated with the mineral concentrations in the
serum of infants at 4 months of age. Human milk and serum mineral content
was estimated by Atomic Absorbtion Spectroscopy. Fe deficiency was
evaluated in postpartum mothers and infants at 4 months of age. The effects
of serum Fe and Zn concentrations on cell-mediated immunity were examined
in postpartum mothers and infants at 4 months of age. T cell subsets and NK
cells percentages were determined by Flow Cytometry.
Results: Fe and Zn contents were 0,42¡À0,15 and 4,6¡À1mg/L in
colostrum; 0,39¡À0,13 and 2,73¡À1,25 mg/L at 1 month; 0,37¡À0,13 and 1,57¡À1,06
mg/L at 4 months, respectively. Zn concentration decreased significantly
throughout the course of lactation but Fe showed no difference. There was
no correlation found amoung the mineral concentrations in maternal serum,
breast milk and serum of infants.
The prevalance of Fe
deficiency anemia was higher in infants fed breast milk (37,5%) than those
who received mixed feeding (27%). Fe deficiency anemia was observed in 40,7
% of all the mothers. In infants who were breast fed higher prevalance of
anemia were associated with low Fe content of human milk. Poor prenatal
care and lack of Fe supplementation were responsible for anemia in mothers.
No effect of Fe
deficiency anemia or feeding regym in infants on cell-mediated immunity
could be discerned. Similarly no effect of Fe deficiency on cell-mediated
immunity in mothers observed. T cell subsets and NK cells percentages were
found in normal ranges in both breast and mixed feeding infants and
mothers.
Both groups of infants
growth patterns were found similar and no effect of Fe deficiency on growth
rate was detected.
Conclusions: The iron content of human milk is low and infants
receiving exclusively breast milk have high risk for Fe deficiency anemia.
There is a need for screening for Fe deficiency anemia in breast fed
infants and supplement Fe should be given after four months of age. Fe
deficiency anemia must be diagnosed and treated early in pregnancy.