Nutrient Reference Values - Public Consultation on Draft Recommendations for Iodine

Overview

NHMRC is inviting feedback on updated Draft Recommendations for Iodine, to be included in the Nutrient Reference Values Australia and New Zealand.

What are Nutrient Reference Values?

The Nutrient Reference Values (NRVs) are evidence-based guidelines that describe how much of each nutrient – like iodine – people should consume to stay healthy. By providing a scientific foundation for both individual nutrition and public health decision making, NRVs help to improve the overall health of the population and reduce the burden of diet-related diseases in Australia and New Zealand.

Why have the iodine NRVs been reviewed?

Iodine is a critical micronutrient required for the synthesis of thyroid hormones, which are essential for growth, development, and metabolic regulation. Getting enough iodine is especially important during pregnancy and early childhood to support normal brain and physical development. However, having too much iodine can also be harmful. That’s why it’s important to have the right balance of iodine in the diet.

The current NRVs for iodine were published in 2006. Since that time, new scientific evidence has emerged regarding iodine requirements across different population groups, particularly in relation to pregnancy, lactation, and early childhood development. In addition, changes in dietary patterns, food fortification practices, and iodine status monitoring data have highlighted the need to reassess the adequacy of existing recommendations.

How were the recommendations developed?

The review process was guided by the 2025 NHMRC NRV Methodological framework and conducted in accordance with the NHMRC Standards for Guidelines. It considered evidence from a range of sources, including published systematic reviews and primary studies, Australian and New Zealand population data, and advice published by key international bodies. The various evidence sources were summarised and synthesised in an Evidence Summary Report. The report also includes an Evidence-to-Decision framework, documenting how the evidence was weighed and considered when arriving at the final recommendations.

An Iodine Expert Working Group – comprised of experts in iodine, nutrition, toxicology, endocrinology and methodology – advised on the conduct of the review and final recommendations. Additional advice on methods for deriving NRVs was provided by a Steering Group Advisory Committee.

What has changed with the revised iodine NRVs?

Recommendations for adults (including during pregnancy and breastfeeding), children, and adolescents have been reviewed. Infant NRVs have not been reviewed at this time, and will be the subject of a separate review in due course.

The current recommendations for iodine comprise:

• Estimated Average Requirements (EAR) and Recommended Dietary Intake (RDI) for achieving nutritional adequacy and preventing iodine deficiency
• Upper Levels (UL) that should not be exceeded to prevent harmful effects from excess iodine.

The main changes proposed relate to the UL, with the EAR and RDI unchanged, including:

• reduced UL recommendations for almost all age groups (except young children)
• update to the methods for deriving EAR and RDI recommendations, to reflect recent evidence and current methodology.

The draft recommendations also include recommendations for additional age groupings for children, aligned with school level, which facilitate comparison against intakes reported in national surveys. A slight adjustment to adult age groups is also proposed, aligned with Australian Bureau of Statistics reporting.

Further information

For further information on NRVs and the updated iodine recommendations, see our Frequently Asked Questions.

How can I make a submission?

Submissions should be made via the online form (click 'Share your views' below).

The form invites responses on questions covering a range of topics and provides space for additional comments. This is an opportunity to provide any additional feedback not covered in the consultation questions.  

You do not have to respond to all questions. Please focus on the topics of most interest to you and/or your organisation.

The closing date for submissions is 11 December 2025. Late submissions will not be accepted.

Other NHMRC public consultations

NHMRC's 2025 Methodological Framework for the Review of Nutrient Reference Values also is currently out for public consultation.

Why your views matter

The information provided during this consultation will help us to understand whether our guidance has considered all relevant factors and is appropriate and implementable. Your feedback will help to improve our recommendations about iodine requirements, ensuring that it is as relevant and user-friendly as possible.