A dose-response crossover iodine balance study to determine iodine requirements in early infancy

卷:104

Dold, Susanne ; Zimmermann, Michael B. ; Baumgartner, Jeannine ; Davaz, Tabea ; Galetti, Valeria ; Braegger, Christian ; Andersson, Maria

ETH

关键词: iodine;    infants;    iodine requirement;    iodine balance;    iodine intake;    iodine deficiency;   

DOI  :  10.3945/ajcn.116.134049

学科分类：食品科学和技术

【 摘 要 】

Background: Optimal iodine intake during infancy is critical for brain development, but no estimated average requirement (EAR) is available for this age group. Objective: We measured daily iodine intake, excretion, and retention over a range of iodine intakes in early infancy to determine the minimum daily intake required to achieve iodine balance. Design: In a dose-response crossover study, we randomly assigned healthy infants (n = 11; mean +/- SD age 13 +/- 3 wk) to sequentially consume over 33 d 3 infant formula milks (IFMs) containing 10.5, 19.3, and 38.5 mu g I/100 kcal, respectively. Each IFM was consumed for 11 d, consisting of a 6-d run-in period followed by a 4-d balance period and 1 run-out day. Results: Iodine intake (mean +/- SD: 54.6 +/- 8.1, 142.3 +/- 23.1, and 268.4 32.6 mu g/d), excretion (55.9 +/- 8.6, 121.9 +/- 21.7, and 228.7 +/- 39.3 mu g/d), and retention (-1.6 +/- 8.3, 20.6 +/- 21.6, and 39.8 +/- 34.3 mu g/d) differed among the low, middle, and high iodine IFM groups (P < 0.001 for all). There was a linear relation between daily iodine intake and both daily iodine excretion and daily iodine retention. Zero balance (iodine intake = iodine excretion, iodine retention = 0 mu g/d) was achieved at a daily iodine intake of 70 mu g (95% CI: 60, 80 mu g). Conclusion: Our data indicate the iodine requirement in 2- to 5-mo-old infants is 70 mu g/d. Adding an allowance for accumulation of thyroidal iodine stores would produce an EAR of 72 mu g and a recommended dietary allowance of 80 mu g.