title: Iron supplements reduce erythrocyte copper-zinc superoxide dismutase activity in term, breastfed infants.
abstract: OBJECTIVE
  To investigate whether iron supplements compromise copper status in infants.
  
  
  METHODS
  214 healthy, term, breastfed Swedish and Honduran infants were randomized to (1) iron supplements (1 mg/kg/d) from 4-9 mo of age, (2) iron supplements from 6-9 mo, or (3) placebo. Blood samples were obtained at 4, 6, and 9 mo and analyzed for plasma copper (p-Cu) and, at 9 mo, for copper/zinc-dependent superoxide dismutase (CuZn-SOD) activity.
  
  
  RESULTS
  P-Cu increased with infant age. At 9 mo, Honduran infants had significantly higher p-Cu (1.40+/-0.29 vs 1.09+/-0.22 mg/l, p<0.001) and CuZn-SOD activity (1.09+/-0.29 vs 0.93+/-0.21 U/mg Hb, p<0.001) than Swedish infants. Infants receiving iron supplements from 4-9 mo had significantly lower CuZn-SOD at 9 mo of age (0.95+/-0.27 vs 1.08+/-0.24 U/mg Hb, p=0.023) than those receiving placebo.
  
  
  CONCLUSIONS
  There is a physiologic increase in p-Cu during the first 9 mo of life. Differences in copper status between Swedish and Honduran infants may be due to genetic or nutritional differences. Iron supplementation decreases CuZn-SOD activity, probably due to a negative effect on copper status. Possible clinical implications remain to be elucidated.
authors.affiliation: Department of Clinical Sciences, Pediatrics, Umeå University, Umeå, Sweden. magnus.domellof@pediatri.umu.se
authors.forename: Magnus
authors.initials: M
authors.lastname: Domellöf
authors.forename: Kathryn G
authors.initials: KG
authors.lastname: Dewey
authors.forename: Roberta J
authors.initials: RJ
authors.lastname: Cohen
authors.forename: Bo
authors.initials: B
authors.lastname: Lönnerdal
authors.forename: Olle
authors.initials: O
authors.lastname: Hernell
mesh_terms: D000328:Adult; D000367:Age Factors; D001942:Breast Feeding; D003300:Copper / Q000097:blood*; D003431:Cross-Cultural Comparison; D019587:Dietary Supplements / Q000009:adverse effects*; D005260:Female; D005296:Ferrous Compounds / Q000009:adverse effects*; D006721:Honduras; D006801:Humans; D007223:Infant; D016014:Linear Models; D008297:Male; D015999:Multivariate Analysis; D013482:Superoxide Dismutase / Q000097:blood* / Q000187:drug effects; D013548:Sweden
chemical_list: D005296:Ferrous Compounds; C020748:ferrous sulfate; D003300:Copper; D013482:Superoxide Dismutase