Iron AbsorptionNCT07921433
Iron Absorption From a Nutritional Iron Supplement
A study testing Iron-Enriched Hydrogel Supplement (A with breakfast), Iron-Enriched Hydrogel Supplement (B with breakfast) and Iron-Enriched Hydrogel Supplement (A without breakfast) in people with Iron Absorption and Iron Deficiencies, run by ETH Zurich at 1 site in Switzerland.
Trial summary
Conventional oral iron supplements often cause gastrointestinal side effects and are limited by poor bioavailability, leaving unabsorbed iron to reach the colon. Hydrocolloid-based hydrogel matrix formulations designed for gradual iron release present a promising approach to improve iron absorption. Read more about this study
- Who is it for?
- Ages 18 to 45 years, women only
- Conditions the study is for
- Iron Absorption, Iron Deficiencies
- What is being tested?
- Iron-Enriched Hydrogel Supplement (A with breakfast), Iron-Enriched Hydrogel Supplement (B with breakfast) and Iron-Enriched Hydrogel Supplement (A without breakfast)
- Type of treatment
- Pill or oral medicine
- Could I receive a placebo?
- No, everyone receives an active treatment
- How many people
- 22 participants
- Where
- 1 siteSwitzerland
- Study dates
- Nov 2026to Feb 2027
- Phase
- Interventional
- Are there results?
- Not yet: the study is under way
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 45 years
- Women only
- No healthy volunteers
- Adult
Who may be able to join
- Female aged 18 to 45 years
- Plasma ferritin <30 µg/L
- Body mass index (BMI) 18.5 kg/m2 - 24.9 kg/m2.
- Body weight <65 kg.
- Signed informed consent
- Sufficient command of English (mother tongue or B2 level)
Who cannot join
- Anemia, defined as hemoglobin (Hb) <120 g/L (<12.0 g/dL).
- Elevated systemic inflammatory markers (C-reactive protein >5.0 mg/L).
- Chronic digestive, renal and/or metabolic diseases
- Chronic medications (except for contraceptives)
- Use of vitamin, mineral, or pre-/Pprobiotic supplements in the 2 weeks before or during the study
- Blood transfusion, blood donation or significant blood loss (>400ml) over the past 4 months
Show all 21Show fewer
- Difficulty with blood withdrawal
- Pregnancy (tested in serum/urine) or intention to become pregnant during the course of the study
- Lactation
- Previous participation in a study using stable isotopes or participation in any clinical study within the last 30 days
- Participants who cannot be expected to comply with the study protocol (e.g. not available on certain study appointments)
- Inability to understand the information sheet and the informed consent form due to cognitive or language reasons
- Smoking (>1 cigarette/week)
- Vegan diet (the standardized breakfast contains plain whole milk yogurt and butter)
- Special exclusion criteria for participants in the MRI imaging sub-study (n=9):
- Presence of a heart pacemaker, neurostimulator, or any other active implanted electronic device.
- Use of a hearing aid that cannot be safely removed for the MRI examination.
- Use of removable dentures that cannot be safely removed for the MRI examination.
- History of surgery on the head or heart involving implanted material that is not confirmed MRI-safe.
- Presence of metallic objects in the body (e.g. implants, magnets, metal splinters, gunshot fragments, tattoos, piercings, or surgical clips) that are not confirmed MRI-safe.
- History of metal splinter injury (e.g. ocular foreign body) or occupational exposure associated with increased risk of retained metal fragments.
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Switzerland1 site, 1 recruiting
- Recruiting
ETH Zürich, Laboratory of Clinical Biopharmacy
Zurich, Canton of Zurich, 8006
Camarena, +41446328393, seline.camarena@pharma.ethz.ch
About this study
Conventional oral iron supplements often cause gastrointestinal side effects and are limited by poor bioavailability, leaving unabsorbed iron to reach the colon. Hydrocolloid-based hydrogel matrix formulations designed for gradual iron release present a promising approach to improve iron absorption. This study evaluates fractional iron absorption (FIA) from three low-dose hydrogel formulations containing ferrous fumarate compared with ferrous fumarate without a hydrogel matrix. Test products will be administered with water, with and without a standardized breakfast. All formulations will be intrinsically labelled with stable iron isotopes ( 57Fe or 54Fe), and FIA will be determined 14 days after administration based on erythrocyte iron incorporation. In this randomized, within-subject corssover study conducted in non-anemic, iron-depleted women, each participant will receive all test conditions and serve as her own control.
- Conditions
- Iron Absorption, Iron Deficiencies
- Being tested
- Iron-Enriched Hydrogel Supplement (A with breakfast), Iron-Enriched Hydrogel Supplement (B with breakfast), Iron-Enriched Hydrogel Supplement (A without breakfast), Iron-Enriched Hydrogel Supplement (B without breakfast), Iron-Enriched Hydrogel Supplement (C with breakfast)
- Medical subject headings
- Iron Deficiencies
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
Iron-Enriched Hydrogel Supplement (A with breakfast)Dietary supplement
Also called FeHydroA
FeHydro-A (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + Standardized Breakfast
Iron-Enriched Hydrogel Supplement (B with breakfast)Dietary supplement
Also called FeHydro B
FeHydro-B (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + Standardized Breakfast
Iron-Enriched Hydrogel Supplement (A without breakfast)Dietary supplement
FeHydro-A (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + 300 mL Water
Iron-Enriched Hydrogel Supplement (B without breakfast)Dietary supplement
FeHydro-B (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + 300 mL Water
Iron-Enriched Hydrogel Supplement (C with breakfast)Dietary supplement
FeHydro-C (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + Standardized Breakfast
Control (FeFum, with breakfast)Dietary supplement
Control (20 mg elemental iron as ferrous fumarate without hydrogel matrix, in gelatin capsule; labeled with 57Fe or 54Fe) + Standardized Breakfast
Control (FeFum, without breakfast)Dietary supplement
Control (20 mg elemental iron as ferrous fumarate without hydrogel matrix, in gelatin capsule; labeled with 57Fe or 54Fe) + 300 mL Water
| Study group | Role | What they receive |
|---|---|---|
| FeHydro-A with breakfast (Condition 1) | Experimental | FeHydro-A with sodium ascorbate, consumed with a standardized breakfast Receives: Dietary Supplement: Iron-Enriched Hydrogel Supplement (A with breakfast) |
| FeHydro-B with breakfast (Condition 2) | Experimental | FeHydro-B without sodium ascorbate, consumed with a standardized breakfast Receives: Dietary Supplement: Iron-Enriched Hydrogel Supplement (B with breakfast) |
| FeHydro-A without breakfast (Condition 3) | Experimental | FeHydro-A with sodium ascorbate, consumed without breakfast Receives: Dietary Supplement: Iron-Enriched Hydrogel Supplement (A without breakfast) |
| FeHydro-B without breakfast (Condition 4) | Experimental | FeHydro-B without sodium ascorbate, consumed without breakfast Receives: Dietary Supplement: Iron-Enriched Hydrogel Supplement (B without breakfast) |
| FeHydro-C with breakfast (Condition 5) | Experimental | FeHydro-C with sodium ascorbate and gum arabic, consumed with a standardized breakfast Receives: Dietary Supplement: Iron-Enriched Hydrogel Supplement (C with breakfast) |
| Control with breakfast (Condition 6) | Active comparator | Control ferrous fumarate, consumed with a standardized breakfast Receives: Dietary Supplement: Control (FeFum, with breakfast) |
| Control without breakfast (Condition 7) | Active comparator | Control ferrous fumarate, consumed without breakfast Receives: Dietary Supplement: Control (FeFum, without breakfast) |
What is being measured
The primary outcome is the main question the study is designed to answer.
Fractional Iron Absorption
Fractional iron absorption will be calculated based on the shift of the iron isotope ratios in red blood cells
Measured: 14 days after administration of each labelled test condition
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted6 Nov 2026
- Study startNov 2026 (estimated)
- Primary completionDec 2026 (estimated)
- Study completionFeb 2027 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Other trials for Iron AbsorptionStudies 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
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind
- Who is masked
- Participant
- Enrolment
- 22 participants (estimated)
Sponsor and investigators
- Lead sponsor
- ETH Zurich
- Sponsor type
- University, hospital or other
- Collaborators
- Swiss Distance University of Applied Sciences
- Responsible party
- Principal investigator, Nicole Stoffel, ETH Zurich
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07921433
- Sponsor's protocol ID
- IRONH
- Status last verified
- Sep 2026
- First submitted
- 2 Nov 2026
- Last updated
- 6 Nov 2026
- Results posted
- No
- Data monitoring committee
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- No: Individual participant data (IPD) will not be made publicly available to protect participant privacy and maintain confidentiality regarding proprietary formulation data. De-identified, aggregated study results and primary outcome data will be published in peer-reviewed scientific journals and made available via public study registries upon completion of the trial.
Study at a glance
From the registry record, last updated by the sponsor on 6 Nov 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Iron Absorption From a Nutritional Iron Supplement
- ClinicalTrials.gov ID
- NCT07921433
- Acronym / sponsor ID
- IRONH
- Conditions
- Iron Absorption, Iron Deficiencies
- Study type
- Interventional
- Recruitment status
- Recruiting
- Enrolment
- 22 participants (estimated)
- Lead sponsor
- ETH ZurichUniversity, hospital or other
- Collaborators
- Swiss Distance University of Applied Sciences
- Study start
- Nov 2026 (estimated)
- Primary completion
- Dec 2026 (estimated)
- Study completion
- Feb 2027 (estimated)
- First posted
- 6 Nov 2026 (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.
Conventional oral iron supplements often cause gastrointestinal side effects and are limited by poor bioavailability, leaving unabsorbed iron to reach the colon. Hydrocolloid-based hydrogel matrix formulations designed for gradual iron release present a promising approach to improve iron absorption. This study evaluates fractional iron absorption (FIA) from three low-dose hydrogel formulations containing ferrous fumarate compared with ferrous fumarate without a hydrogel matrix. Test products will be administered with water, with and without a standardized breakfast. All formulations will be intrinsically labelled with stable iron isotopes ( 57Fe or 54Fe), and FIA will be determined 14 days after administration based on erythrocyte iron incorporation. In this randomized, within-subject corssover study conducted in non-anemic, iron-depleted women, each participant will receive all test conditions and serve as her own control.
Study design
- Primary purpose
- Other
- Allocation
- Randomised
- Intervention model
- Crossover
- Masking
- Single blind (participant)
- Number of arms
- 7
| Arm | Type | Receives |
|---|---|---|
| FeHydro-A with breakfast (Condition 1) | Experimental | Dietary Supplement: Iron-Enriched Hydrogel Supplement (A with breakfast)FeHydro-A with sodium ascorbate, consumed with a standardized breakfast |
| FeHydro-B with breakfast (Condition 2) | Experimental | Dietary Supplement: Iron-Enriched Hydrogel Supplement (B with breakfast)FeHydro-B without sodium ascorbate, consumed with a standardized breakfast |
| FeHydro-A without breakfast (Condition 3) | Experimental | Dietary Supplement: Iron-Enriched Hydrogel Supplement (A without breakfast)FeHydro-A with sodium ascorbate, consumed without breakfast |
| FeHydro-B without breakfast (Condition 4) | Experimental | Dietary Supplement: Iron-Enriched Hydrogel Supplement (B without breakfast)FeHydro-B without sodium ascorbate, consumed without breakfast |
| FeHydro-C with breakfast (Condition 5) | Experimental | Dietary Supplement: Iron-Enriched Hydrogel Supplement (C with breakfast)FeHydro-C with sodium ascorbate and gum arabic, consumed with a standardized breakfast |
| Control with breakfast (Condition 6) | Active comparator | Dietary Supplement: Control (FeFum, with breakfast)Control ferrous fumarate, consumed with a standardized breakfast |
| Control without breakfast (Condition 7) | Active comparator | Dietary Supplement: Control (FeFum, without breakfast)Control ferrous fumarate, consumed without breakfast |
Who may qualify
- Ages
- 18 to 45 years
- Sex
- Female only
- Healthy volunteers
- Not accepted
- Age groups
- Adult
Key inclusion criteria (6 listed)
- Female aged 18 to 45 years
- Plasma ferritin <30 µg/L
- Body mass index (BMI) 18.5 kg/m2 - 24.9 kg/m2.
- Body weight <65 kg.
- Signed informed consent
Key exclusion criteria (21 listed)
- Anemia, defined as hemoglobin (Hb) <120 g/L (<12.0 g/dL).
- Elevated systemic inflammatory markers (C-reactive protein >5.0 mg/L).
- Chronic digestive, renal and/or metabolic diseases
- Chronic medications (except for contraceptives)
- Use of vitamin, mineral, or pre-/Pprobiotic supplements in the 2 weeks before or during the study
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 |
|---|---|---|
| Iron-Enriched Hydrogel Supplement (A with breakfast)Also: FeHydroAFeHydro-A (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + Standardized Breakfast | Dietary supplement | FeHydro-A with breakfast (Condition 1) |
| Iron-Enriched Hydrogel Supplement (B with breakfast)Also: FeHydro BFeHydro-B (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + Standardized Breakfast | Dietary supplement | FeHydro-B with breakfast (Condition 2) |
| Iron-Enriched Hydrogel Supplement (A without breakfast)FeHydro-A (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + 300 mL Water | Dietary supplement | FeHydro-A without breakfast (Condition 3) |
| Iron-Enriched Hydrogel Supplement (B without breakfast)FeHydro-B (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + 300 mL Water | Dietary supplement | FeHydro-B without breakfast (Condition 4) |
| Iron-Enriched Hydrogel Supplement (C with breakfast)FeHydro-C (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + Standardized Breakfast | Dietary supplement | FeHydro-C with breakfast (Condition 5) |
| Control (FeFum, with breakfast)Control (20 mg elemental iron as ferrous fumarate without hydrogel matrix, in gelatin capsule; labeled with 57Fe or 54Fe) + Standardized Breakfast | Dietary supplement | Control with breakfast (Condition 6) |
| Control (FeFum, without breakfast)Control (20 mg elemental iron as ferrous fumarate without hydrogel matrix, in gelatin capsule; labeled with 57Fe or 54Fe) + 300 mL Water | Dietary supplement | Control without breakfast (Condition 7) |
Primary outcome
Fractional Iron Absorption
Time frame: 14 days after administration of each labelled test condition
Fractional iron absorption will be calculated based on the shift of the iron isotope ratios in red blood cells
Results and safety
This study is still under way. Results are not available in the source record yet.
Research links
- Official record on ClinicalTrials.govLast updated by the sponsor 6 Nov 2026.
- Individual participant dataSharing planned: No. Individual participant data (IPD) will not be made publicly available to protect participant privacy and maintain confidentiality regarding proprietary formulation data. De-identified, aggregated study results and primary outcome data will be published in peer-reviewed scientific journals and made available via public study registries upon completion of the trial.
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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.
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
A study testing Iron-Enriched Hydrogel Supplement (A with breakfast), Iron-Enriched Hydrogel Supplement (B with breakfast) and Iron-Enriched Hydrogel Supplement (A without breakfast) in people with Iron Absorption and Iron Deficiencies, run by ETH Zurich at 1 site in Switzerland.
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 6 inclusion and 21 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: looking for participants now, as of the sponsor's last update on 6 Nov 2026. 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 Switzerland. 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?
This study is still under way. Results are not available in the source record yet.
How can a doctor refer a patient or contact the research team?
Contact Camarena (+41446328393, seline.camarena@pharma.ethz.ch), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Fractional Iron Absorption (time frame: 14 days after administration of each labelled test condition). 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 6 Nov 2026.