Mode of oral iron administration and the amount of iron habitually consumed do not affect iron absorption, systemic iron utilisation or zinc absorption in iron-sufficient infants: a randomised trial

• Published in: British journal of nutrition 2016-09, Vol.116 (6), p.1046-1060
• Main Authors: Szymlek-Gay, Ewa A., Domellöf, Magnus, Hernell, Olle, Hurrell, Richard F., Lind, Torbjörn, Lönnerdal, Bo, Zeder, Christophe, Egli, Ines M.
• Format: Article
• Language: English
• Subjects: Absorption; Administration, Oral; Babies; Baby foods; Dietary supplements; Double-Blind Method; Drug Interactions; Food fortification; Human and Clinical Nutrition; Humans; Infant; Infant Nutritional Physiological Phenomena; Infants; Iron; Iron - administration & dosage; Iron - pharmacokinetics; Zinc; Zinc - pharmacokinetics
• ISSN: 0007-1145; 1475-2662; 1475-2662
• DOI: 10.1017/S0007114516003032

Different metabolic pathways of supplemental and fortification Fe, or inhibition of Zn absorption by Fe, may explain adverse effects of supplemental Fe in Fe-sufficient infants. We determined whether the mode of oral Fe administration or the amount habitually consumed affects Fe absorption and systemic Fe utilisation in infants, and assessed the effects of these interventions on Zn absorption, Fe and Zn status, and growth. Fe-sufficient 6-month-old infants (n 72) were randomly assigned to receive 6·6 mg Fe/d from a high-Fe formula, 1·3 mg Fe/d from a low-Fe formula or 6·6 mg Fe/d from Fe drops and a formula with no added Fe for 45 d. Fractional Fe absorption, Fe utilisation and fractional Zn absorption were measured with oral (57Fe and 67Zn) and intravenous (58Fe and 70Zn) isotopes. Fe and Zn status, infection and growth were measured. At 45 d, Hb was 6·3 g/l higher in the high-Fe formula group compared with the Fe drops group, whereas serum ferritin was 34 and 35 % higher, respectively, and serum transferrin 0·1 g/l lower in the high-Fe formula and Fe drops groups compared with the low-Fe formula group (all P