Chapter Eight: Discussion
8.4 Concluding remarks
The findings from this thesis provide a unique contribution to nutrition science and add important information to the limited available data regarding the iodine nutrition of Victorian school-aged children post fortification of bread with iodised salt. Furthermore, the studies included in this thesis have highlighted a number of challenges to overcome with regards to the current methods used for assessing the iodine nutrition of populations. Therefore, validation of current recommendations is needed using a more sensitive biomarker of iodine nutrition, such as thyroglobulin, to ensure that the iodine nutrition of populations is being accurately assessed. Based on the findings from this thesis, it would appear that the iodine intakes of Victorian school-aged children have improved to sufficient levels since the introduction of mandatory iodine fortification in 2009, with bread and milk being the main contributors to total iodine intake. The main source of iodine within bread comes from the iodised salt added during processing, therefore the implementation of sodium reduction targets as a means of reducing population sodium intakes, may have a negative impact on the iodine status of Victorian school-aged children. As sodium reduction should remain an important public health initiative for reducing the risk of cardiovascular disease, such targets should also take into account the potential impact which their implementation may have on the iodine content of foods such as bread. In addition, alternative strategies for improving iodine intakes through foods which are less reliant on iodised salt for their iodine content, such as milk, need to be considered by health professionals and government bodies. In summary, the evidence linking both iodine deficiency and excess to adverse health outcomes in school-aged children provides
Discussion
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substantial rationale for the implementation of an ongoing population iodine monitoring program in Australia. Furthermore, such a program will help to further elucidate the success of mandatory fortification and enable the monitoring of the impact of various public health strategies, such as the application of sodium reduction targets to bread, on the iodine nutrition of the population.
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