This article in Journal of Pediatrics, September 1995 127;429-31 is quite
interesting.  The authors, Pisacone at al,. found that in breastfed infants
given no other milks nor medicinal iron, iron enriched formula or cereal had
less anemia the longer they had breastfed!!

I quote the abstract:"None of the infants who were 'exclusively' [I question
their definition of this, but still...] breast fed for 7 months or more and
43% of those who were breastfed for a shorter time were anemic.  Infatns who
were exclusively breast fed for a prolonged period had a good iron status at
12 and 24 months.

Of course in their discussion 'a very long time'  to breastfeed means 7
months or longer!!
And my impression is that other foods were consumed, just not iron enhanced
ones.

Mardrey Swenson