title: True absorption and retention of supplemental iron is more efficient when iron is administered every three days rather than daily to iron-normal and iron-deficient rats.
abstract: Absorption of daily iron supplements is inefficient. Detailed absorption patterns of FeSO4 supplements simulating World Health Organization-recommended doses were studied in iron-deficient and iron-normal male Sprague-Dawley rats. For 12 d after weaning, the rats were fed a premeal containing < 20 (iron-deficient group) or 400 micrograms Fe (iron-normal group) twice daily followed by iron-free AIN-76 diet for 1 h. Then, both groups (iron-deficient and -normal) were divided in three groups, one continuing without change and two receiving 4000 micrograms of premeal Fe either daily or every 3 d to match intestinal mucosa renewal time. Food intake, growth, hemoglobin concentration and periodic 59Fe-labeled iron absorption and rate of loss were determined. Iron-deficient rats became anemic, and ate and grew less. Iron absorption was stable in normal (34.2%), deficient (89.7%) and normal, intermittently supplemented (9.5%) groups. Absorption decreased logarithmically in daily supplemented rats, whereas in iron-deficient, intermittently supplemented rats absorption decreased slowly and linearly. Rates of iron loss were significantly accelerated in daily supplemented rats. Thirteen-day total iron retention in intermittently supplemented normal and deficient rats was 62 and 86%, respectively, of that of daily supplemented rats. Iron supplementation timed to match mucosal renewal is more efficient.
authors: Department of Nutritional Sciences, University of California, Berkeley 94720.
authors: F E
authors: FE
authors: Viteri
authors: X
authors: X
authors: Liu
authors: K
authors: K
authors: Tolomei
authors: A
authors: A
authors: Martín
mesh_terms: D000042:Absorption; D000818:Animals; D004334:Drug Administration Schedule; D006454:Hemoglobins / Q000032:analysis; D007501:Iron / Q000008:administration & dosage / Q000493:pharmacokinetics*; D000090463:Iron Deficiencies; D008297:Male; D010865:Pilot Projects; D051381:Rats; D017207:Rats, Sprague-Dawley; D014886:Weaning
chemical_list: D006454:Hemoglobins; D007501:Iron