Iodine status of breastfed infants and their mothers' breast milk iodine concentration

• Published in: Maternal & Child Nutrition
• Main Authors: Petersen, Erna, Thorisdottir, Birna, Thorsdottir , Inga, Gunnlaugsson, Geir, Arohonka, Petra, Erlund, Iris, Gunnarsdottir, Ingibjorg
• Other Authors: Matvæla- og næringarfræðideild (HÍ), Faculty of Food Science and Nutrition (UI), Félagsfræði-, mannfræði- og þjóðfræðideild (HÍ), Faculty of Sociology, Anthropology and Folkloristics (UI), Heilbrigðisvísindasvið (HÍ), School of Health Sciences (UI), Félagsvísindasvið (HÍ), School of Social Sciences (UI), Háskóli Íslands, University of Iceland
• Format: Article in Journal/Newspaper
• Language: English
• Published: Wiley 2020
• Subjects: Diet; Human; Infant; Iodine; Lactation; Milk; Mataræði; Brjóstagjöf; Joð; Iceland
• Online Access: https://hdl.handle.net/20.500.11815/2313; https://doi.org/10.1111/mcn.12993

Publisher's version (útgefin grein) Iodine is an essential nutrient for growth and development during infancy. Data on iodine status of exclusively (EBF) and partially breastfed (PBF) infants as well as breast milk iodine concentration (BMIC) are scarce. We aimed to assess (a) infant iodine nutrition at the age of 5.5 months by measuring urinary iodine concentration (UIC) in EBF (n = 32) and PBF (n = 28) infants and (b) mothers' breast milk iodine concentration (n = 57). Sixty mother–infant pairs from three primary health care centres in Reykjavik and vicinities provided urine and breast milk samples for iodine analysis and information on mothers' habitual diet. The mother–infant pairs were participants of the IceAge2 study, which focuses on factors contributing to infant growth and development, including body composition and breast-milk energy content. The median (25th–75th percentiles) UIC was 152 (79–239) μg/L, with no significant difference between EBF and PBF infants. The estimated median iodine intake ranged from 52 to 86 μg/day, based on urinary data (assuming an average urine volume of 300–500 ml/day and UIC from the present study). The median (25th–75th percentiles) BMIC was 84 (48–114) μg/L. It is difficult to conclude whether iodine status is adequate in the present study, as no ranges for median UIC reflecting optimal iodine nutrition exist for infants. However, the results add important information to the relatively sparse literature on UIC, BMIC, and iodine intake of breastfed infants. We would like to thank all the infants and their mothers for participat-ing in the study. Furthermore, we are grateful to the primary healthcare centres for their part in the recruitment process. The Iceage2study (Growth and Body Composition in Breastfed Infants: Study onAge of Introduction of Complementary Foods in Iceland, clinicaltrials.gov identifier NCT02586571) was funded by the University of Iceland Research fund. Analysis of UIC and BMIC was funded by NordicWorking Group for Diet, Food & Toxicology ...