title: Iron supplementation of breast-fed Honduran and Swedish infants from 4 to 9 months of age.
abstract: OBJECTIVE
  The objective was to study the effects of iron supplementation on hemoglobin and iron status in 2 different populations.
  
  
  METHODS
  In a randomized, placebo-controlled, masked clinical trial, we assigned term Swedish (n = 101) and Honduran (n = 131) infants to 3 groups at 4 months of age: (1) iron supplements, 1 mg/kg/d, from 4 to 9 months, (2) placebo, 4 to 6 months and iron, 6 to 9 months, and (3) placebo, 4 to 9 months. All infants were breast-fed exclusively to 6 months and partially to 9 months.
  
  
  RESULTS
  From 4 to 6 months, the effect of iron (group 1 vs 2 + 3) was significant and similar in both populations for hemoglobin, ferritin, and zinc protoporphyrin. From 6 to 9 months, the effect (group 2 vs group 3) was significant and similar at both sites for all iron status variables except hemoglobin, for which there was a significant effect only in Honduras. In Honduras, the prevalence of iron deficiency anemia at 9 months was 29% in the placebo group and 9% in the supplemented groups. In Sweden, iron supplements caused no reduction in the already low prevalence of iron deficiency anemia at 9 months (<3%).
  
  
  CONCLUSIONS
  Iron supplementation from 4 to 9 months or 6 to 9 months significantly reduced iron deficiency anemia in Honduran breast-fed infants. The unexpected hemoglobin response at 4 to 6 months in both populations suggests that regulation of hemoglobin synthesis is immature at this age.
authors.affiliation: Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden.
authors.forename: M
authors.initials: M
authors.lastname: Domellöf
authors.forename: R J
authors.initials: RJ
authors.lastname: Cohen
authors.forename: K G
authors.initials: KG
authors.lastname: Dewey
authors.forename: O
authors.initials: O
authors.lastname: Hernell
authors.forename: L L
authors.initials: LL
authors.lastname: Rivera
authors.forename: B
authors.initials: B
authors.lastname: Lönnerdal
mesh_terms: D000367:Age Factors; D018798:Anemia, Iron-Deficiency / Q000453:epidemiology / Q000517:prevention & control*; D001942:Breast Feeding; D019587:Dietary Supplements; D006454:Hemoglobins / Q000378:metabolism; D006721:Honduras / Q000453:epidemiology; D006801:Humans; D007223:Infant; D007501:Iron / Q000097:blood / Q000627:therapeutic use*; D000090463:Iron Deficiencies; D015995:Prevalence; D013548:Sweden / Q000453:epidemiology; D016896:Treatment Outcome
chemical_list: D006454:Hemoglobins; D007501:Iron