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The safety and scientific validity of this study is the responsibility of the study sponsor and investigators. Listing a study does not mean it has been endorsed by the ANZCTR. Before participating in a study, talk to your health care provider and refer to this information for consumers
Trial registered on ANZCTR

Registration number
Ethics application status
Date submitted
Date registered
Date last updated
Type of registration
Retrospectively registered

Titles & IDs
Public title
Effect of iodine and selenium intervention on the thyroid status of older New Zealanders
Scientific title
Effect of iodine and selenium intervention on the thyroid status of older New Zealanders
Universal Trial Number (UTN)
Trial acronym
Linked study record

Health condition
Health condition(s) or problem(s) studied:
Selenium, Iodine and Thyroid Status 463 0
Condition category
Condition code
Metabolic and Endocrine 540 540 0 0
Normal metabolism and endocrine development and function

Study type
Description of intervention(s) / exposure
Participants will be randomised into one of four treatment groups & given a supplement containing either; selenium, iodine, selenium & iodine or placebo. Participants take one supplement daily for 12 weeks. Selenium, iodine and thryoid status of participants will be measured at 5 time point over the intervention.
Intervention code [1] 227 0
Comparator / control treatment
Control group

Primary outcome [1] 631 0
To determine the effects of a 12 week supplementation with iodine and selenium on thyroid status
Timepoint [1] 631 0
Secondary outcome [1] 1304 0
To investigate interactions between selenium and thyroid status
Timepoint [1] 1304 0
At 5 time points over a 12 week period.
Secondary outcome [2] 1305 0
To determine the effects of iodine supplementation, with or without selenium, on throid metabolism as measured by the ratio of the active hormone T3 to the inactive hormone T4.
Timepoint [2] 1305 0
At 5 time points over a 12 week period.

Key inclusion criteria
Plasma Selenium <100ugLPersons not institutionalisedAmbulatoryGood Health with no serious medical illnesses
Minimum age
65 Years
Maximum age
80 Years
Both males and females
Can healthy volunteers participate?
Key exclusion criteria
Institutionalised. Plasma Se >100ugL. Serious Medical Illness

Study design
Purpose of the study
Allocation to intervention
Randomised controlled trial
Procedure for enrolling a subject and allocating the treatment (allocation concealment procedures)
A statistician randomly allocated participants to one of the four groups (A, B, C or D). Participants will be given a tablet bottle containing either tablets A, B, C or D, none of the researchers conducting the study know what supplement type each letter signifies-One person within our department holds the 'code breaker' for the study which tells us what supplement type each letter corresponds to.
Methods used to generate the sequence in which subjects will be randomised (sequence generation)
Statistician used block randomisation & computer software to generate the random allocation sequence
Masking / blinding
Blinded (masking used)
Who is / are masked / blinded?

Intervention assignment
Other design features
Type of endpoint(s)
Statistical methods / analysis

Recruitment status
Date of first participant enrolment
Date of last participant enrolment
Date of last data collection
Sample size
Accrual to date
Recruitment outside Australia
Country [1] 143 0
New Zealand
State/province [1] 143 0

Funding & Sponsors
Funding source category [1] 598 0
Name [1] 598 0
University Melb.Dept. Gen Practice
Address [1] 598 0
Country [1] 598 0
New Zealand
Primary sponsor type
University of Otago, Dunedin, New Zealand
New Zealand
Secondary sponsor category [1] 487 0
Name [1] 487 0
Address [1] 487 0
Country [1] 487 0

Ethics approval
Ethics application status
Ethics committee name [1] 1696 0
University of Otago Human Ethics Committee
Ethics committee address [1] 1696 0
Ethics committee country [1] 1696 0
New Zealand
Date submitted for ethics approval [1] 1696 0
Approval date [1] 1696 0
Ethics approval number [1] 1696 0

Brief summary
Trial website
Trial related presentations / publications
Public notes

Principal investigator
Name 35629 0
Address 35629 0
Country 35629 0
Phone 35629 0
Fax 35629 0
Email 35629 0
Contact person for public queries
Name 9416 0
Jenny Campbell
Address 9416 0
C/- Department of Human Nutrition University of Otago
Union St
PO Box 56
Dunedin 9007
Country 9416 0
New Zealand
Phone 9416 0
+64 3 4795673
Fax 9416 0
Email 9416 0
Contact person for scientific queries
Name 344 0
Associate Professor Christine Thomson
Address 344 0
C/- Department of Human Nutrition University of Otago
Union St
PO Box 56
Dunedin 9007
Country 344 0
New Zealand
Phone 344 0
+64 3 4797943
Fax 344 0
Email 344 0

No information has been provided regarding IPD availability
Summary results
No Results