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Iron Absorption From Plant Heme Iron

Iron Absorption From Plant-Derived Heme Iron: An Experimental Study in Iron-Deficient Women (PHIA)

Status
Completed
Phases
Unknown
Study type
Interventional
Source
ClinicalTrials.gov
Registry ID
NCT07143890
Acronym
PHIA
Enrollment
45
Registered
2025-08-27
Start date
2025-09-22
Completion date
2026-05-26
Last updated
2026-06-02

For informational purposes only — not medical advice. Sourced from public registries and may not reflect the latest updates. Terms

Conditions

Iron Absorption, Iron Deficiency (ID)

Keywords

Iron sulfate, Iron fortification, plant-derived heme iron, Stable isotopes, Iron bioavailability

Brief summary

Heme, an iron protoporphyin IX complex, consists of a ferrous ion captured in a porphyrin ring acting as a tetradentate ligand. The unique features of heme iron -its unusually high absorption in foods and its resistance to luminal inhibitors of iron absorption- make it a potentially interesting iron fortificant. This study aims to compare fractional iron absorption from two plant-derived heme iron compounds-iron chlorophyllin and soy hemoglobin-with ferrous sulfate (negative control) and porcine hemoglobin (positive control) in iron-deficient women. All four compounds will be intrinsically labeled with stable iron isotopes. Fractional absorption will be assessed 14 days after test meal administration via erythrocyte iron incorporation. Absorption will be tested in two matrices: water and maize porridge (an inhibitory matrix). Each participant will consume all test conditions in a randomized order, allowing for within-subject comparisons.

Interventions

OTHERIron chlorophyllin + no-matrix

Water with labelled Fe chlorophyllin (54Fe)

OTHERSoyHb + no-matrix

Water with labelled soy hemoglobin (58Fe)

OTHERFeSO4 + no-matrix

Water with labelled ferrous sulfate (58Fe)

OTHERHb + no-matrix

Water with labelled porcine hemoglobin (57Fe)

OTHERIron chlorophyllin + meal-matrix

Maize porridge with labelled Fe chlorophyllin (54Fe)

OTHERSoyHb + meal-matrix

Maize porridge with labelled soy hemoglobin (58Fe)

Maize porridge with labelled ferrous sulfate (57Fe)

OTHERHb + meal-matrix

Maize porridge with labelled porcine hemoglobin (57Fe)

Sponsors

ETH Zurich
Lead SponsorOTHER

Study design

Allocation
RANDOMIZED
Intervention model
CROSSOVER
Primary purpose
PREVENTION
Masking
SINGLE (Subject)

Eligibility

Sex/Gender
FEMALE
Age
18 Years to 45 Years
Healthy volunteers
Yes

Inclusion criteria

* Serum ferritin \< 45 µg/L (iron depleted) * Body weight \< 70 kg * Body mass index 18,5 - 24,9 kg/m2 (normal weight)

Exclusion criteria

* Hb \< 120 g/L (anemia) * CRP \> 5 µg/L (inflammation) * Strict vegan and vegetarians * Any metabolic, gastrointestinal kidney or chronic disease * Consumption of mineral and vitamin supplements since screening and over the study period until last blood sample collection * Blood transfusion over the past 6 months * blood donation over the past 6 months * Significant blood loss (accident, surgery) over the past 6 months * Women who are pregnant or breast feeding * Smoker (\> 1 cigarette per week) * Continuous/long-term use of medication (except for contraceptives) * Therapeutic iron infusion over the past 6 months, * Known hypersensitivity or allergy to iron supplements, * Intention to become pregnant during the course of the studies, * Known or suspected non-compliance, drug or alcohol abuse, * Inability to follow the procedures of the studies, e.g. due to language problems, psychological disorders, dementia, etc. of the participant, * Participation in another study with investigational drug within the 30 days preceding and during the present studies, * Enrolment of the investigator, his/her family members, employees and other dependent persons

Design outcomes

Primary

MeasureTime frameDescription
Fractional Iron Absorption (percent)Day 22Fractional iron absorption will be calculated based on the shift of the iron isotope ratios in the collected blood samples after the administration of the intervention products. Fractional iron absorption will be measured as erythrocyte incorporation of the naturally occurring iron forms with different masses used to label the iron supplements.

Secondary

MeasureTime frameDescription
Hemoglobin (g/dL)Day 1Iron status marker
Serum Ferritin (µg/L)Day 1Iron status marker
soluble Transferrin Receptor (mg/L)Day 1Iron status marker
C-reactive protein (mg/L)Day 1Chronic inflammation marker
Alpha-1-acid Glycoprotein (g/L)Day 1Acute inflammation marker
Hepcidin (ng/mL)Day 1A major regulator of iron absorption

Countries

Switzerland

Outcome results

None listed

Source: ClinicalTrials.gov · Data processed: Jun 3, 2026