Modelling of dietary iodine intake and excretion

Quintessa’s compartment modelling software, AMBER, has recently been used in a Canadian PhD study, to model the dietary intake and excretion of I-129 and I-127 in human biological materials.

With the recent re-emergence of iodine deficiency among individuals in several industrialised countries, understanding a population’s main sources of iodine population is necessary to ensure fortification strategies are justified and effective. Uncertainty has recently arisen as to the relative importance of iodised salt, especially with medical warnings to reduce salt consumption.

In June 2022, the University of Ottawa published a PhD thesis entitled "An Assessment of Iodine-129 and Iodine 127 in Human Biological Materials with Modelling of Dietary Iodine Intake and Excretion".

This thesis was concerned with iodine status and sources in human body, and measurements in human materials in the Canadian population. Using I-129 as a tracer, a new method was developed to extract I-129 from urine, and an existing method to extract I-129 from breastmilk refined. Subsequently, a biokinetic model of iodine, developed by Leggett (2017), was implemented in the AMBER compartment modelling software (see figure below). This model was used to investigate the main sources of I-127 and I-129 in the Canadian diet based on daily food consumption survey data, and modelling of the urinary iodine concentration for adults and infants. The influence of seven common diets on urinary iodine concentrations were assessed to determine which foods play an important role in ensuring iodine adequacy. It was observed that the main source of iodine in a vegan diet is grain products providing up to 70%, while in remaining diets the main source of iodine was dairy products (50-69%), when they are consumed. The contribution of iodised salt to all Canadian diets was ranked second, after dairy, unless the diet is vegan or ovo-vegetarian, where dairy is not consumed; iodised salt was ranked first for those two diets.

If you are interested in using AMBER to support academic research, please contact us directly.

A screenshot from the AMBER software. This shows a colour-coded network of compartments, represented as labelled boxes, neatly organised. Each compartment represents a different place where iodine may reside, such as liver, blood, thyroid, kidney, urine. Transfers between compartments are represented by arrows. Each transfer between compartments represents a possible pathway for iodine.
The Leggett (2017) biokinetic model of iodine implemented in AMBER. A new compartment (Urine_Sink) and a new transfer (Urine_TO_Urine_Sink) were added to the model as part of the PhD research; these are shown in white.