The idea that the iron in infant formula predisposes infants to
constipation is perhaps the oldest urban legend kicking around
pediatric offices. The belief that iron in infant formula can
create problems for babies may be an extension of the misery
experienced by pregnant women when supplemented with iron. When
they’ve experienced the effects of iron supplementation, new
mothers will often take matters into their own hands.
Pediatricians themselves desperate for relief from colicky
parents will often gamble with the low-iron card. It’s estimated
that low-iron formulas account for 9%-30% of elective infant
formula sales in the United States. So what are the facts? Let’s
look at a typical 6 kilogram 3-month-old infant consuming an
average of 28 ounces per day formula. An infant fed Enfamil
Lipil low-iron receives 4.2 mg of iron per day. The same volume
of standard Enfamil Lipil provides 10.1 mg of iron daily. It’s
estimated that babies need about 1 mg of iron per kilogram of
bodyweight. The baby in our example