An interventional study of Iron-Enriched Hydrogel Supplement (A with breakfast) and Iron-Enriched Hydrogel Supplement (B with breakfast) in Iron Absorption and Iron Deficiencies, sponsored by ETH Zurich. Recruiting at 1 site in Switzerland. Open to female participants aged 18 Years to 45 Years. Per ClinicalTrials.gov, last updated 2026-11-06.
Sponsored by ETH Zurich · Not applicable, Interventional, and Other
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.
386 studies on the registry are indexed under Iron Deficiencies; 80 are open to participants now.
This study's planned enrollment of 22 is below the median of 99 across 301 interventional studies indexed under Iron Deficiencies.
Browse Iron Deficiencies studies →ETH Zurich is the lead sponsor of 20 studies on the registry; 12 are open to participants now.
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Go through the criteria one by one — yes, no or not sure — and take the list to your doctor or the study team. Kept in this browser only.
Exclusion Criteria:
Special exclusion criteria for participants in the MRI imaging sub-study (n=9):
Underlined terms in the criteria open these too. Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
BMI (body mass index)
Weight in kilograms divided by height in metres squared. Example: 70 kg and 1.75 m gives 70 ÷ (1.75 × 1.75) ≈ 22.9.
What counts as overweight or obesity differs between countries (some use lower cut-offs), so go by the range the study states.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Informed consent
Before you join, the study team explains what taking part involves — its purpose, what happens, the risks and possible benefits — and answers your questions, so you can decide freely. Consent is usually recorded on a form (the informed consent form, ICF) signed by you or, where the law allows, by someone legally authorised to decide for you.
You can keep asking questions during the study, you are told of new information that matters, and you can choose to leave at any time.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Hemoglobin (Hb)
The protein in red blood cells that carries oxygen. A low level is anaemia, which can cause tiredness and breathlessness. Measured in g/dL or g/L (9 g/dL is 90 g/L).
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
Contraception
Ways of preventing pregnancy. “Highly effective” methods fail less than 1% of the time a year when used correctly — for example an IUD or an implant.
Criteria usually say which methods count and how long to keep using them after the last dose, sometimes for male participants too. Some studies accept a partner’s vasectomy if it was confirmed successful and that person is the participant’s only sexual partner.
Explained by clinicaltrials.gg, not part of the registry record. The study team decides who can take part.
FeHydro-A with sodium ascorbate, consumed with a standardized breakfast
Dietary Supplement: Iron-Enriched Hydrogel Supplement (A with breakfast)
FeHydro-B without sodium ascorbate, consumed with a standardized breakfast
Dietary Supplement: Iron-Enriched Hydrogel Supplement (B with breakfast)
FeHydro-A with sodium ascorbate, consumed without breakfast
Dietary Supplement: Iron-Enriched Hydrogel Supplement (A without breakfast)
FeHydro-B without sodium ascorbate, consumed without breakfast
Dietary Supplement: Iron-Enriched Hydrogel Supplement (B without breakfast)
FeHydro-C with sodium ascorbate and gum arabic, consumed with a standardized breakfast
Dietary Supplement: Iron-Enriched Hydrogel Supplement (C with breakfast)
Control ferrous fumarate, consumed with a standardized breakfast
Dietary Supplement: Control (FeFum, with breakfast)
Control ferrous fumarate, consumed without breakfast
Dietary Supplement: Control (FeFum, without breakfast)
FeHydro-A (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + Standardized Breakfast
Also known as: FeHydroA
FeHydro-B (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + Standardized Breakfast
Also known as: FeHydro B
FeHydro-A (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + 300 mL Water
FeHydro-B (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + 300 mL Water
FeHydro-C (20 mg elemental iron as ferrous fumarate embedded in hydrogel matrix; labeled with 57Fe or 54Fe) + Standardized Breakfast
Control (20 mg elemental iron as ferrous fumarate without hydrogel matrix, in gelatin capsule; labeled with 57Fe or 54Fe) + Standardized Breakfast
Control (20 mg elemental iron as ferrous fumarate without hydrogel matrix, in gelatin capsule; labeled with 57Fe or 54Fe) + 300 mL Water
Fractional Iron Absorption
Fractional iron absorption will be calculated based on the shift of the iron isotope ratios in red blood cells
Time frame: 14 days after administration of each labelled test condition
Plan to share: 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.
No publications or documents are linked to this record.
From the registry record's own update history. This site started tracking changes on Sep 25, 2026; for anything earlier, see the record history on ClinicalTrials.gov ↗
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