Iodine BioavailabilityNCT04867031
Impact of the Food Matrix on Iodine Bioavailability
A study testing Milk, Fish and Seaweed in people with Iodine Bioavailability, run by University of Glasgow at 1 site in United Kingdom.
Trial summary
This study is a randomized crossover trial, lasting 12 days in total, which will assess the difference in iodine bioavailability (as a percentage of iodine consumed that is excreted in urine) from three iodine-rich foods; semi-skimmed milk, white fish, and dried seaweed sheets. Read more about this study
- Who is it for?
- Ages 18 to 48 yearsHealthy volunteers can take part
- Conditions the study is for
- Iodine Bioavailability
- What is being tested?
- Milk, Fish and Seaweed
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 13 participants
- Where
- 1 siteUnited Kingdom
- Study dates
- 26 Aug 2017to 3 Jul 2018
- Phase
- Interventional
- Are there results?
- None posted in the registry
Key requirements
Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.
- Ages 18 to 48 years
- All sexes
- Healthy volunteers accepted
- Adult
Who may be able to join
- Healthy
- Male or female
- Aged 18-48
- Signed informed consent
Who cannot join
- Pregnancy and lactation
- Past and present thyroid conditions
- Diseases of the gastrointestinal tract
- Allergy to seafood or dairy
- Consumption of iodine supplements
- Currently taking medication (other than the contraceptive pill)
- Having a habitual diet very low in iodine (<1 portion of dairy per day, or < 1 portion of fish per week)
Trial locations and contacts
1 site in 1 country.
United Kingdom1 site
Section of Human Nutrition, University of Glasgow
Glasgow, North Lanarkshire, G31 2ER
About this study
This study is a randomized crossover trial, lasting 12 days in total, which will assess the difference in iodine bioavailability (as a percentage of iodine consumed that is excreted in urine) from three iodine-rich foods; semi-skimmed milk, white fish, and dried seaweed sheets. Each of the three foods will provide approximately 140µg of iodine, and iodine excretion will be monitored for 36 hours following food ingestion via collection and analysis of urine.
Read the detailed description
Iodine insufficiency is one of the three key micronutrient deficiencies highlighted as major public health issues by the World Health Organisation, and recent evidence indicates that the UK is now iodine deficient. Iodine deficiency represents a particular threat for women of child-bearing age, unborn infants and young children, as iodine is essential to synthesise the thyroid hormones, which are involved in key metabolic function including fetal brain development. Maternal iodine deficiency and the resulting changes in thyroid function has been associated with adverse pregnancy outcomes including spontaneous miscarriage, fetal distress and death, preterm delivery, low birth weight and impaired neuropsychological development, with significant impact on later life development and quality of life.
There is no iodine fortification programme in the United Kingdom, and despite worldwide efforts to tackle iodine deficiency and associated disorders via iodine supplementation and food-fortification (of salt mainly), consumption of supplements in the UK is virtually non-existent, with iodised salt used by less than 5%.
In the UK, the main dietary sources of iodine are dairy and sea-foods. Our previous studies have shown that seaweed intake can increase the iodine status of women with diets habitually low in iodine. Reduced bioavailability of iodine from the seaweed matrix, which could have implications for dietary recommendations.
This study address the influence of the food matrix on iodine bioavailability, in the context of food guidelines and assessment of the iodine status.
This project is in collaboration with the British Broadcast Corporation (BBC).
The study design is a crossover randomised trial - to last 9 days, plus three days pre-trial washout [total 12 days] - with 3 arms:
- fish arm: portion equivalent to 140 µg iodine, approx. 130g.
- milk arm: portion equivalent to 140 µg iodine, approx. 450mL.
- seaweed arm: portion equivalent to 140 µg iodine, approx. 6g.
Each arm will be separated by two washout days, and participants will follow a low iodine diet (avoiding dairy, and all seafood) throughout the study, as well as three days prior to the first arm. Iodine levels will be monitored in urine collected during the 12 hours preceding and 36 hours following the meal. Urine will be collected in time fractions
A parallel design study showed that 56% (SD 20%) of a dose of potassium iodide is excreted after 24hours, compared to 36% (SD 13%) when the same dose comes from seaweed. In order to detect a similar difference, a sample of at least 13 participants is required (n=19 to allow for 30% attrition).
- Conditions
- Iodine Bioavailability
- Being tested
- Milk, Fish, Seaweed
- Keywords
- iodine, bioavailability, seaweed, milk, fish
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
MilkDietary supplement
One portion of semi-skimmed cow's milk (approx. 450mL), providing ~140µg of iodine.
FishDietary supplement
One portion of cod (approx. 130g), providing ~140µg of iodine.
SeaweedDietary supplement
One portion of dried seaweed sheets (approx. 6g), providing ~140µg of iodine.
| Study group | Role | What they receive |
|---|---|---|
| White fish (cod) | Experimental | Participants will consume 1 portion (~130g) of white fish (Bird's Eye Inspirations Cod Fillets with Tomato \& Rosemary), providing approximately 140µg of iodine, alongside 452mL of water. Urine will be collected for 36 hours following test food consumption. Receives: Dietary Supplement: Fish |
| Semi-skimmed milk | Experimental | Participants will consume 1 portion (~450mL) of milk (Tesco UHT Semi-Skimmed), providing approximately 140µg of iodine, alongside 452mL of water. Urine will be collected for 36 hours following test food consumption. Receives: Dietary Supplement: Milk |
| Dried seaweed sheets | Experimental | Participants will consume 1 portion (~6g) of dried seaweed sheets (Itsu Crispy Seaweed Thins), providing approximately 140µg of iodine, alongside 452mL of water. Urine will be collected for 36 hours following test food consumption. Receives: Dietary Supplement: Seaweed |
What is being measured
The primary outcome is the main question the study is designed to answer.
Iodine concentration in urine (µg/L)
Measured using the Sandell-Kolthoff method
Measured: 36 hours (fractions: 1-2, 2-3, 3-5, 5-7, 7-12, 12-24, 24-36 hours)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted30 Apr 2021
- Study start26 Aug 2017
- Primary completion3 Jul 2018
- Study completion3 Jul 2018
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Iodine BioavailabilityStudies of the same condition, open and under way.
- What the trial phases meanHow a treatment moves from first tests in people to approval.
More details
For doctors and researchers: how the study is designed, who runs it, and its registry IDs.
Study design
- Study type
- Interventional
- Phase
- Phase N/A
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Enrolment
- 13 participants (actual)
Sponsor and investigators
- Lead sponsor
- University of Glasgow
- Sponsor type
- University, hospital or other
- Collaborators
- British Broadcasting Corporation
- Responsible party
- Principal investigator, Emilie Combet, University of Glasgow
- Investigators
- Emilie Combet, PhD, Principal investigator, University of Glasgow
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04867031
- Sponsor's protocol ID
- 200160161
- Status last verified
- Jan 2023
- First submitted
- 27 Apr 2021
- Last updated
- 10 Jan 2023
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided
Study at a glance
From the registry record, last updated by the sponsor on 10 Jan 2023. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Impact of the Food Matrix on Iodine Bioavailability
- ClinicalTrials.gov ID
- NCT04867031
- Acronym / sponsor ID
- 200160161
- Conditions
- Iodine Bioavailability
- Keywords
- iodine, bioavailability, seaweed, milk, fish
- Study type
- Interventional
- Recruitment status
- Completed
- Enrolment
- 13 participants (actual)
- Lead sponsor
- University of GlasgowUniversity, hospital or other
- Collaborators
- British Broadcasting Corporation
- Study start
- 26 Aug 2017 (actual)
- Primary completion
- 3 Jul 2018 (actual)
- Study completion
- 3 Jul 2018 (actual)
- First posted
- 30 Apr 2021 (actual)
- Results
- Not posted in the source record
Clinical summary
The research question as the sponsor registered it. This describes what the study plans to test, not what it found.
This study is a randomized crossover trial, lasting 12 days in total, which will assess the difference in iodine bioavailability (as a percentage of iodine consumed that is excreted in urine) from three iodine-rich foods; semi-skimmed milk, white fish, and dried seaweed sheets. Each of the three foods will provide approximately 140µg of iodine, and iodine excretion will be monitored for 36 hours following food ingestion via collection and analysis of urine.
Detailed description
Iodine insufficiency is one of the three key micronutrient deficiencies highlighted as major public health issues by the World Health Organisation, and recent evidence indicates that the UK is now iodine deficient. Iodine deficiency represents a particular threat for women of child-bearing age, unborn infants and young children, as iodine is essential to synthesise the thyroid hormones, which are involved in key metabolic function including fetal brain development. Maternal iodine deficiency and the resulting changes in thyroid function has been associated with adverse pregnancy outcomes including spontaneous miscarriage, fetal distress and death, preterm delivery, low birth weight and impaired neuropsychological development, with significant impact on later life development and quality of life.
There is no iodine fortification programme in the United Kingdom, and despite worldwide efforts to tackle iodine deficiency and associated disorders via iodine supplementation and food-fortification (of salt mainly), consumption of supplements in the UK is virtually non-existent, with iodised salt used by less than 5%.
In the UK, the main dietary sources of iodine are dairy and sea-foods. Our previous studies have shown that seaweed intake can increase the iodine status of women with diets habitually low in iodine. Reduced bioavailability of iodine from the seaweed matrix, which could have implications for dietary recommendations.
This study address the influence of the food matrix on iodine bioavailability, in the context of food guidelines and assessment of the iodine status.
This project is in collaboration with the British Broadcast Corporation (BBC).
The study design is a crossover randomised trial - to last 9 days, plus three days pre-trial washout [total 12 days] - with 3 arms:
- fish arm: portion equivalent to 140 µg iodine, approx. 130g.
- milk arm: portion equivalent to 140 µg iodine, approx. 450mL.
- seaweed arm: portion equivalent to 140 µg iodine, approx. 6g.
Each arm will be separated by two washout days, and participants will follow a low iodine diet (avoiding dairy, and all seafood) throughout the study, as well as three days prior to the first arm. Iodine levels will be monitored in urine collected during the 12 hours preceding and 36 hours following the meal. Urine will be collected in time fractions
A parallel design study showed that 56% (SD 20%) of a dose of potassium iodide is excreted after 24hours, compared to 36% (SD 13%) when the same dose comes from seaweed. In order to detect a similar difference, a sample of at least 13 participants is required (n=19 to allow for 30% attrition).
Study design
- Primary purpose
- Basic science
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- None (open label)
- Number of arms
- 3
| Arm | Type | Receives |
|---|---|---|
| White fish (cod) | Experimental | Dietary Supplement: FishParticipants will consume 1 portion (~130g) of white fish (Bird's Eye Inspirations Cod Fillets with Tomato \& Rosemary), providing approximately 140µg of iodine, alongside 452mL of water. Urine will be collected for 36 hours following test food consumption. |
| Semi-skimmed milk | Experimental | Dietary Supplement: MilkParticipants will consume 1 portion (~450mL) of milk (Tesco UHT Semi-Skimmed), providing approximately 140µg of iodine, alongside 452mL of water. Urine will be collected for 36 hours following test food consumption. |
| Dried seaweed sheets | Experimental | Dietary Supplement: SeaweedParticipants will consume 1 portion (~6g) of dried seaweed sheets (Itsu Crispy Seaweed Thins), providing approximately 140µg of iodine, alongside 452mL of water. Urine will be collected for 36 hours following test food consumption. |
Who may qualify
- Ages
- 18 to 48 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
Key inclusion criteria (4 listed)
- Healthy
- Male or female
- Aged 18-48
- Signed informed consent
Key exclusion criteria (7 listed)
- Pregnancy and lactation
- Past and present thyroid conditions
- Diseases of the gastrointestinal tract
- Allergy to seafood or dairy
- Consumption of iodine supplements
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Interventions
| Intervention | Type | Arms |
|---|---|---|
| MilkOne portion of semi-skimmed cow's milk (approx. 450mL), providing ~140µg of iodine. | Dietary supplement | Semi-skimmed milk |
| FishOne portion of cod (approx. 130g), providing ~140µg of iodine. | Dietary supplement | White fish (cod) |
| SeaweedOne portion of dried seaweed sheets (approx. 6g), providing ~140µg of iodine. | Dietary supplement | Dried seaweed sheets |
Primary outcome
Iodine concentration in urine (µg/L)
Time frame: 36 hours (fractions: 1-2, 2-3, 3-5, 5-7, 7-12, 12-24, 24-36 hours)
Measured using the Sandell-Kolthoff method
Results and safety
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 10 Jan 2023.
- Individual participant dataSharing planned: Undecided
Related trials for Iodine Bioavailability
Not yet recruiting
Bioavailability of Micronutrients With a Special Focus on Vitamin K Dependent on Consumed Diet
Micronutrient Status
Active, not recruiting
The Bioavailability of Iodine in Plant-based Milk Alternatives
Iodine Deficiency
Referral and contact
AzTrials does not enrol participants or take referrals. Contact the study team or a site listed below; they decide who can take part. This study is not recruiting at the moment.
Emilie Combet, PhD principal investigator
University of Glasgow
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Milk, Fish and Seaweed in people with Iodine Bioavailability, run by University of Glasgow at 1 site in United Kingdom.
The full registered description is in the About this study section and the official record.
Who may be eligible to take part?
The sponsor lists 4 inclusion and 7 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.
Is this clinical trial currently recruiting?
The record says: finished, as of the sponsor's last update on 10 Jan 2023. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 1 site in United Kingdom. Whether a site is taking part right now should be confirmed with that site. See every site.
What are the possible benefits and risks?
They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.
Are results available for this study?
The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.
How can a doctor refer a patient or contact the research team?
The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Iodine concentration in urine (µg/L) (time frame: 36 hours (fractions: 1-2, 2-3, 3-5, 5-7, 7-12, 12-24, 24-36 hours)). It is what the study was designed to measure, not a finding.
Where can I read the original study information?
Does a listing mean the treatment is approved or proven to work?
No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.
How often is this information updated?
AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 10 Jan 2023.