Adverse effects of cow's milk in infants

[Guest guest]

1: Nestle Nutr Workshop Ser Pediatr Program. 2007;60:185-96; discussion

196-9.

Adverse effects of cow's milk in infants.

Ziegler EE.

Fomon Infant Nutrition Unit, Department of Pediatrics, University of Iowa,

Iowa City, IA, USA.

The feeding of cow's milk has adverse effects on iron nutrition in

infants and young children. Several different mechanisms have been

identified that may act synergistically. Probably most important is

the low iron content of cow's milk. It makes it difficult for the

infant to obtain the amounts of iron needed for growth. A second

mechanism is the occult intestinal blood loss, which occurs in about

40% of normal infants during feeding of cow's milk. Loss of iron in

the form of blood diminishes with age and ceases after 1 year of age.

A third factor is calcium and casein provided by cow's milk in high

amounts. Calcium and casein both inhibit the absorption of dietary

nonheme iron. Infants fed cow's milk receive much more protein and

minerals than they need. The excess has to be excreted in the urine.

The high renal solute load leads to higher urine concentration during

the feeding of cow's milk than during the feeding of breast milk or

formula. When fluid intakes are low and/or when extrarenal water

losses are high, the renal concentrating ability of infants may be

insufficient for maintaining water balance in the face of high water

use for excretion of the high renal solute. The resulting negative

water balance, if prolonged, can lead to serious dehydration. There is

strong epidemiological evidence that the feeding of cow's milk or

formulas with similarly high potential renal solute load places

infants at an increased risk of serious dehydration. The feeding of

cow's milk to infants is undesirable because of cow's milk's

propensity to lead to iron deficiency and because it unduly increases

the risk of severe dehydration.

PMID: 17664905