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dc.contributor.advisorSkeaff, Sheila
dc.contributor.advisorMcLean, Rachel
dc.contributor.authorDavies, Briar Jean
dc.identifier.citationDavies, B. J. (2016). Iodine status of 8-10 year olds in New Zealand Post Iodine Fortification of Bread (Thesis, Master of Dietetics). University of Otago. Retrieved from
dc.description.abstractBackground: The trace element, iodine, plays a vital role in the composition and function of thyroid hormones and consequently normal human growth and development. New Zealand (NZ) soils have low iodine concentrations and iodine deficiency has been a recurring problem since the early 1900’s. Iodised salt was introduced to NZ in 1924 and was effective until the late 20th century when iodine deficiency re-emerged due to changes in food manufacturing, the dairy industry and food habits. In 2009, fortification of bread with iodised salt was mandated by the NZ government to increase iodine intakes and improve the iodine status of New Zealanders. One small study (n=147) was conducted in 2011 on 8-10 year old school children living in Dunedin and Wellington but further research was required. Aim: To determine the effectiveness of mandatory iodine fortification of bread on the iodine status on a larger and more representative sample of 8-10 year old children residing in Auckland and Christchurch. Methods: A cross-sectional school-based cluster survey was conducted on 8-10 year olds residing in Auckland and Christchurch (n=445). In March and April 2015, children were asked to give a casual urine sample, a blood spot sample, had their weight and height measured, and were administered a short questionnaire combining questions on demographics and an iodine-specific food frequency questionnaire (FFQ). Laboratory analysis was used to determine median urinary iodine concentration (UIC), and the blood spot samples to analyse Thyroglobulin (Tg) concentrations. Analysis and results from the blood spot samples are not presented in this thesis. Estimated total iodine intake and the contribution from major food groups to total dietary iodine intake was calculated from the FFQ. Results: The median UIC of children (n=415) was 116µg/L, falling within the World Health Organisation (WHO)/ United Nations International Children’s Emergency Fund (UNICEF)/ Iodine Global Network (IGN) recommended range of 100-299µg/L indicating an adequate iodine status. Thirty-eight percent of children had a median UIC <100µg/L and 5% had a median UIC <50µg/L. There were significant differences in mean UIC’s between genders (male = 126µg/L, female = 107µg/L, p<0.001) and ethnicities (NZ/European/Pakeha = 110µg/L, Maori = 110 µg/L, Pacific = 133 µg/L, Asian = 151 µg/L, p=0.006). From the iodine-specific FFQ, total iodine intake was 63µg/day, from ‘food only’. When including discretionary use of iodised salt, total iodine intake was 101µg/day indicating this study’s sample is meeting NZ’s estimated average requirement (EAR) (75µg/day). The FFQ also showed that the food group ‘bread, bread products and bread-based dishes’ was the greatest contributor to iodine intake, providing 52% of total dietary iodine. Conclusions: The mandatory fortification of bread with iodised salt has resulted in adequate iodine status of a representative sample of children living in Auckland and Christchurch.
dc.publisherUniversity of Otago
dc.rightsAll items in OUR Archive are provided for private study and research purposes and are protected by copyright with all rights reserved unless otherwise indicated.
dc.subjectiodine, children, New Zealand, fortification
dc.titleIodine status of 8-10 year olds in New Zealand Post Iodine Fortification of Bread
dc.language.rfc3066en Nutrition of Dietetics of Otago
otago.openaccessAbstract Only
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