A dose-response crossover iodine balance study to determine iodine requirements in early infancy
Zimmermann, Michael B.
MetadataShow full item record
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 6 SD age 13 6 3 wk) to sequentially consume over 33 d 3 infant formula milks (IFMs) containing 10.5, 19.3, and 38.5 mg 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 6 SD: 54.6 6 8.1, 142.3 6 23.1, and 268.4 6 32.6 mg/d), excretion (55.9 6 8.6, 121.9 6 21.7, and 228.7 6 39.3 mg/d), and retention (21.6 6 8.3, 20.6 6 21.6, and 39.8 6 34.3 mg/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 mg/d) was achieved at a daily iodine intake of 70 mg (95% CI: 60, 80 mg). Conclusion: Our data indicate the iodine requirement in 2- to 5-moold infants is 70 mg/d. Adding an allowance for accumulation of thyroidal iodine stores would produce an EAR of 72 mg and a recommended dietary allowance of 80 mg. This trial was registered at clinicaltrials.gov as NCT02045784
- Faculty of Health Sciences 
Showing items related by title, author, creator and subject.
Iodine status assessment in South African adults according to spot urinary iodine concentrations, prediction equations, and measured 24-h iodine excretion Charlton, Karen E.; Ware, Lisa J.; Baumgartner, Jeannine; Cockeran, Marike; Schutte, Aletta E. (MDPI, 2018)The iodine status of populations is conventionally assessed using spot urinary samples to obtain a median urinary iodine concentration (UIC) value, which is assessed against standard reference cut-offs. The assumption that ...
Breast-milk iodine concentrations, iodine status, and thyroid function of breastfed infants aged 2-4 months and their mothers residing in a South African township Osei, Jennifer; Smuts, Cornelius M.; Baumgartner, Jeannine; Andersson, Maria; Van der Reijden, Olivia; Dold, Susanne (Galenos Yayincilik, 2016)Objective: Lactating women and their infants are susceptible to iodine deficiency and iodine excess. In South Africa, no data exist on the iodine status and thyroid function of these vulnerable groups. Methods: In a ...
Optimization of a new mass spectrometry method for measurement of breast milk iodine concentrations and an assessment of the effect of analytic method and timing of within: feed sample collection on breast milk iodine concentrations Dold, Susanne; Baumgartner, Jeannine; Osei, Jennifer; Zeder, Christophe; Krzystek, Adam (Mary Ann Liebert, Inc, 2016)Background: Breast milk iodine concentration (BMIC) may be an indicator of iodine status during lactation, but there are few data comparing different analytical methods or timing of sampling. The aims of this study were: ...