Objective: To investigate the relationship between iron status in infancy and type of milk and weaning solids consumed.
Design: An observational cohort study.
Setting: 928 term infants from Avon Longitudinal Study of Parents and Children, during 1993 to 1994.
Methods: Haemoglobin and ferritin concentrations at 8 and 12 months were assessed in relation to dietary intake at 8 months. Infants were divided into groups depending on the type and quantity of milk being taken.
Results: By WHO criteria, 22.7% were anaemic at 8 months and 18.1% at 12 months. More infants being fed breast milk were anaemic at 8 & 12 months compared to those fed formula. Being fed cows' milk, as the main drink, was associated with increased anaemia at 12 months and low ferritin at 8 & 12 months. No association was found between intake of any nutrients and haemoglobin concentrations. Protein and non-haem iron intakes were positively associated with ferritin concentrations and calcium intake negatively. This effect was more marked in infants being fed cows' milk. More than a quarter of infants in the breast milk and cows’ milk groups had iron intakes below the lower reference nutrient intake (LRNI) and as high as 41% in infants having > 6 breast feeds per day. Feeding cows' milk or formula above 600ml or > 6 breastfeeds per day was associated with lower intakes of solids.
Conclusions: Both breast and cows' milk feeding were associated with higher levels of anaemia. Achieving satisfactory iron intake from solids during the latter part of infancy is more likely if formula intake is < 600ml per day and if breast-fed infants are limited to < 6 feeds per day. Cows' milk should be strongly discouraged as a main drink before 12 months.
- breast milk
- cows' milk
- iron deficiency