It seems to widely agreed now that full term babies usually do fine regarding their iron status for six months if predominently breast-fed (using the WHO definition). What happens if they are exclusively breast-fed has presumably not been studied, as so few researchers have used careful definitions and so few babies are exclusively breast-fed for that long. It may be the case that additions of almost anything to the infant diet affect absorption of iron from breast milk, and thus exclusively breast-fed infants may well on average do well for longer than six months. In one Finnish study, "exclusively" breast fed infants did better than those fed iron fortified cereals until 6 months of age at which time those still not receiving solids declined until by nine months of age they were at about the same level as the supplemented infants. However, 6/36 were removed from the study before 9 months of age and given supplementary iron due to signs of iron deficiency (not anemia though). Ref: Siimes MA et al. Exclusive breast-feeding for 9 months: risk of iron deficiency. J Pediatr 104:196-199, 1984. JA McMillan et al (Iron sufficiency in breast-fed infants and the availability of iron from human milk. Pediatrics 58:686-691, 1976) followed 4 infants until 18 months of age and found no serious iron deficiency. RA Pastel et al (Iron sufficiency with prolonged exclusive breastfeeding in Peruvian infants. Clinical Pediatrics 20:625-6, 1981) found no sign of iron deficiency in seven exclusively breast-fed Peruvian infants age 7.5-12 months (mean 9.3). Many other studies have arrived at a less positive estimation of the relationship between breastfeeding and infant iron status, but all that I have seen either paid little attention to what supplements were given or, though they claimed the infants were exclusively breast-fed, did not check this carefully enough to convince one that this was indeed the case. More research is needed on this as for many other outcomes, among infants fed nothing but human milk for varying periods of time. Ted Greiner, PhD Senior Lecturer in International Nutrition Unit for International Child Health, Entrance 11 Uppsala University 75185 Uppsala Sweden phone +46 - 18 511598 fax +46 - 18 515380 e-mail [log in to unmask]