Anemia, Iron DeficiencyFeGenesNCT04198545
Ethnic Differences in Iron Absorption (FeGenes)
An observational study of Anemia, Iron Deficiency and Iron Overload, run by Cornell University at 2 sites in United States.
Trial summary
This study aims to; 1) investigate population differences in iron absorption between East Asians and Northern Europeans; 2) assess population differences in hormonal and biochemical determinants of Fe absorption between East Asians and Northern Europeans; and 3) to investigate genetic contributions to Fe absorption… Read more about this study
- Who is it for?
- Ages 18 to 50 yearsHealthy volunteers can take part
- Conditions the study is for
- Anemia, Iron Deficiency, Iron Overload
- How many people
- 515 participants
- Where
- 2 sitesUnited States
- Study dates
- 1 Aug 2019to 31 Dec 2026
- Phase
- Observational
- 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 50 years
- All sexes
- Healthy volunteers accepted
- Adult
Study population: Healthy adults from Ithaca and Rochester, NY
Who may be able to join
- Healthy adults
- Age between 18- 50y
- Non-smoking
- Not taking vitamin or mineral supplements.
- Females: premenopausal and not pregnant or lactating
- No preexisting medical complications (such as eating disorders, hemoglobinopathies, malabsorption diseases, steroid use, substance abuse history, or taking medications known to influence iron homeostasis)
- Body mass index (BMI) between 18 - 30 kg/m2.
Who cannot join
- BMI <18 or > 30 kg/m2,
- Age <18 y or > 50y,
- Not of Northern European or East Asian ancestry
- Smoking
- Pregnancy, lactating
- Have gastrointestinal disorders/malabsorption diseases/hemoglobinopathies/dietary restrictions/steroid use/ medication use of medications known to impact iron status, iron utilization or inflammatory status
- Take vitamin and mineral supplementations
Trial locations and contacts
2 sites in 1 country.
United States2 sites
Cornell University
Ithaca, New York, 14853
University of Rochester
Rochester, New York, 14642
About this study
Official title: Ethnic Differences in Iron Absorption
This study aims to; 1) investigate population differences in iron absorption between East Asians and Northern Europeans; 2) assess population differences in hormonal and biochemical determinants of Fe absorption between East Asians and Northern Europeans; and 3) to investigate genetic contributions to Fe absorption, Fe status and Fe regulatory hormones between East Asians and Northern Europeans.
Read the detailed description
Detailed description:
This study will utilize a multidisciplinary approach to identify genetic variation in genes that control iron utilization in order to shed light on the genetic basis of population differences in iron status and disease susceptibility with a long-term goal of informing population-specific dietary iron intake recommendations to minimize the risk of chronic diseases. To evaluate iron utilization, we will employ an in vivo, functional approach using an oral stable iron isotope method. Each participant will have genetic ancestry and genotyping evaluated using the Illumina Global Diversity Array-8. Study participants (n=504, aged 18-50 y) will consume 57Fe (as ferrous sulfate) in the fasted state and will then ingest a standardized breakfast and lunch meal. Two weeks after iron dosing, a blood sample will be collected from each participant and the amount of 57Fe incorporated into red blood cells will be measured using magnetic sector thermal ionization mass spectrometry. This project will fundamentally advance our understanding of ethnic differences in nutrient metabolism and iron status. It will also provide information to assist with the long-term goal of reducing the public health burden of Fe-related diseases.
- Conditions
- Anemia, Iron Deficiency, Iron Overload
- Keywords
- Iron absorption, Genetics
- Medical subject headings
- Anemia, Iron-Deficiency, Iron Overload
What is being measured
The primary outcome is the main question the study is designed to answer.
The percent of non-heme iron absorption
The percent of non-heme iron absorption will be determined by red blood cell iron incorporation of stable 57Fe
Measured: 2-week
The concentrations of iron and micronutrient status indicators
The concentrations or serum folate, B12, hemoglobin, hematocrit, transferrin receptor, hepcidin, erythropoietin, erythroferrone, ferritin, interleukin-6, and c-reactive protein
Measured: baseline and two-weeks post dosing
Genetic ancestry and characterization of iron-related genotypes
The DNA will be extracted from whole blood samples and each participant will have genetic ancestry and genotyping evaluated using the Illumina Global Diversity Array-8.
Measured: baseline
Habitual dietary information
Habitual dietary information will be obtained from Diet History Questionnaire III .
Measured: baseline
Dietary information on the study day
Detailed dietary information about all foods and beverages consumed on the study day will be obtained from the Automated Self-Administered 24-Hour Dietary Assessment Tool.
Measured: baseline
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted13 Dec 2019
- Study start1 Aug 2019
- Primary completion16 Oct 2023
- Study completion31 Dec 2026 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (6)Papers the sponsor has linked to this study.
- Other trials for Anemia, Iron DeficiencyStudies 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
- Observational
- Observational model
- Case only
- Time perspective
- Cross-sectional
- Enrolment
- 515 participants (actual)
Sponsor and investigators
- Lead sponsor
- Cornell University
- Sponsor type
- University, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH)
- Responsible party
- Sponsor
- Investigators
- Kimberly O O'Brien, Principal investigator, Cornell University
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT04198545
- Sponsor's protocol ID
- IRB # 1904008754
- Other IDs
- R01DK122216
- Acronym
- FeGenes
- Status last verified
- Oct 2026
- First submitted
- 11 Dec 2019
- Last updated
- 23 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
Publications
Lee MR, Barad A, Bender E, Thompson J, Gu Z, Pressman EK, O'Brien KO. Differential associations between menstrual blood loss scores and iron status in East Asian and Northern European individuals: findings from a cross-sectional analysis of the Iron Genes in East Asian and Northern European Adults Study (FeGenes) cohort. Am J Clin Nutr. 2026 Jun;123(6):101326. doi: 10.1016/j.ajcnut.2026.101326. Epub 2026 Apr 25.
PubMed 42044770Barad A, Xu H, Clark AG, Gu Z, Pressman EK, Ye K, O'Brien KO. A genetic association study of iron absorption in adults of East Asian or Northern European ancestry from the Iron Genes in East Asian and Northern European Adults Study (FeGenes). Am J Clin Nutr. 2026 Jun;123(6):101298. doi: 10.1016/j.ajcnut.2026.101298. Epub 2026 Mar 25.
PubMed 41895699Park CY, Barad A, Xu Y, Bender E, Thomas AK, Haller CM, Gu Z, Pressman EK, O'Brien KO. Dietary intake in East Asian and Northern European participants from the FeGenes study. Eur J Nutr. 2025 Jun 5;64(5):205. doi: 10.1007/s00394-025-03730-w.
PubMed 40471375Barad A, Xu Y, Bender E, Pressman EK, Gu Z, O'Brien KO. Differences in nonheme iron absorption between healthy adults of East Asian or Northern European ancestry from the Iron Genes in East Asian and Northern European Adults Study (FeGenes): A cross-sectional stable iron isotope study. Am J Clin Nutr. 2025 Feb;121(2):417-426. doi: 10.1016/j.ajcnut.2024.11.015.
PubMed 39909711Barad A, Xu Y, Bender E, Pressman EK, Gu Z, O'Brien KO. Iron regulatory hormones and their associations with iron status biomarkers among healthy adults of East Asian or Northern European ancestry: A cross-sectional comparison from the Iron Genes in East Asian and Northern European Adults Study (FeGenes). Am J Clin Nutr. 2025 Feb;121(2):406-416. doi: 10.1016/j.ajcnut.2024.10.018.
PubMed 39909710Barad A, Xu Y, Bender E, Kang W, Xu R, Gu Z, Pressman EK, O'Brien KO. Characterization of iron status biomarkers and hematological indices among young adults of East Asian or Northern European ancestry: A cross-sectional analysis from the Iron Genes in East Asian and Northern European Adults Study (FeGenes). Am J Clin Nutr. 2025 Feb;121(2):394-405. doi: 10.1016/j.ajcnut.2024.10.014.
PubMed 39909709
Study at a glance
From the registry record, last updated by the sponsor on 23 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Ethnic Differences in Iron Absorption
- ClinicalTrials.gov ID
- NCT04198545
- Acronym / sponsor ID
- FeGenes / IRB # 1904008754
- Conditions
- Anemia, Iron Deficiency, Iron Overload
- Keywords
- Iron absorption, Genetics
- Study type
- Observational
- Recruitment status
- Active, not recruiting
- Enrolment
- 515 participants (actual)
- Lead sponsor
- Cornell UniversityUniversity, hospital or other
- Collaborators
- National Institute of Diabetes and Digestive and Kidney Diseases (NIDDK), National Institutes of Health (NIH)
- Study start
- 1 Aug 2019 (actual)
- Primary completion
- 16 Oct 2023 (actual)
- Study completion
- 31 Dec 2026 (estimated)
- First posted
- 13 Dec 2019 (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 aims to; 1) investigate population differences in iron absorption between East Asians and Northern Europeans; 2) assess population differences in hormonal and biochemical determinants of Fe absorption between East Asians and Northern Europeans; and 3) to investigate genetic contributions to Fe absorption, Fe status and Fe regulatory hormones between East Asians and Northern Europeans.
Detailed description
Detailed description:
This study will utilize a multidisciplinary approach to identify genetic variation in genes that control iron utilization in order to shed light on the genetic basis of population differences in iron status and disease susceptibility with a long-term goal of informing population-specific dietary iron intake recommendations to minimize the risk of chronic diseases. To evaluate iron utilization, we will employ an in vivo, functional approach using an oral stable iron isotope method. Each participant will have genetic ancestry and genotyping evaluated using the Illumina Global Diversity Array-8. Study participants (n=504, aged 18-50 y) will consume 57Fe (as ferrous sulfate) in the fasted state and will then ingest a standardized breakfast and lunch meal. Two weeks after iron dosing, a blood sample will be collected from each participant and the amount of 57Fe incorporated into red blood cells will be measured using magnetic sector thermal ionization mass spectrometry. This project will fundamentally advance our understanding of ethnic differences in nutrient metabolism and iron status. It will also provide information to assist with the long-term goal of reducing the public health burden of Fe-related diseases.
Study design
- Observational model
- Case only
- Time perspective
- Cross-sectional
Who may qualify
- Ages
- 18 to 50 years
- Sex
- All
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- Healthy adults from Ithaca and Rochester, NY
Key inclusion criteria (7 listed)
- Healthy adults
- Age between 18- 50y
- Non-smoking
- Not taking vitamin or mineral supplements.
- Females: premenopausal and not pregnant or lactating
Key exclusion criteria (7 listed)
- BMI <18 or > 30 kg/m2,
- Age <18 y or > 50y,
- Not of Northern European or East Asian ancestry
- Smoking
- Pregnancy, lactating
Eligibility is decided by the study team after screening; this overview does not establish that a patient qualifies. Full inclusion and exclusion criteria.
Primary outcome
The percent of non-heme iron absorption
Time frame: 2-week
The percent of non-heme iron absorption will be determined by red blood cell iron incorporation of stable 57Fe
The concentrations of iron and micronutrient status indicators
Time frame: baseline and two-weeks post dosing
The concentrations or serum folate, B12, hemoglobin, hematocrit, transferrin receptor, hepcidin, erythropoietin, erythroferrone, ferritin, interleukin-6, and c-reactive protein
Genetic ancestry and characterization of iron-related genotypes
Time frame: baseline
The DNA will be extracted from whole blood samples and each participant will have genetic ancestry and genotyping evaluated using the Illumina Global Diversity Array-8.
Habitual dietary information
Time frame: baseline
Habitual dietary information will be obtained from Diet History Questionnaire III .
Dietary information on the study day
Time frame: baseline
Detailed dietary information about all foods and beverages consumed on the study day will be obtained from the Automated Self-Administered 24-Hour Dietary Assessment Tool.
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 23 Oct 2026.
- Derived from this study: PubMed 42044770Lee MR, Barad A, Bender E, Thompson J, Gu Z, Pressman EK, O'Brien KO. Differential associations between menstrual blood loss scores and iron status in East Asian and Northern European individuals: findings from a cross-sectional analysis of the Iron Genes in East Asian and Northern European Adults Study (FeGenes) cohort. Am J Clin Nutr. 2026 Jun;123(6):101326. doi: 10.1016/j.ajcnut.2026.101326. Epub 2026 Apr 25.
- Derived from this study: PubMed 41895699Barad A, Xu H, Clark AG, Gu Z, Pressman EK, Ye K, O'Brien KO. A genetic association study of iron absorption in adults of East Asian or Northern European ancestry from the Iron Genes in East Asian and Northern European Adults Study (FeGenes). Am J Clin Nutr. 2026 Jun;123(6):101298. doi: 10.1016/j.ajcnut.2026.101298. Epub 2026 Mar 25.
- Derived from this study: PubMed 40471375Park CY, Barad A, Xu Y, Bender E, Thomas AK, Haller CM, Gu Z, Pressman EK, O'Brien KO. Dietary intake in East Asian and Northern European participants from the FeGenes study. Eur J Nutr. 2025 Jun 5;64(5):205. doi: 10.1007/s00394-025-03730-w.
- Derived from this study: PubMed 39909711Barad A, Xu Y, Bender E, Pressman EK, Gu Z, O'Brien KO. Differences in nonheme iron absorption between healthy adults of East Asian or Northern European ancestry from the Iron Genes in East Asian and Northern European Adults Study (FeGenes): A cross-sectional stable iron isotope study. Am J Clin Nutr. 2025 Feb;121(2):417-426. doi: 10.1016/j.ajcnut.2024.11.015.
- Derived from this study: PubMed 39909710Barad A, Xu Y, Bender E, Pressman EK, Gu Z, O'Brien KO. Iron regulatory hormones and their associations with iron status biomarkers among healthy adults of East Asian or Northern European ancestry: A cross-sectional comparison from the Iron Genes in East Asian and Northern European Adults Study (FeGenes). Am J Clin Nutr. 2025 Feb;121(2):406-416. doi: 10.1016/j.ajcnut.2024.10.018.
- Derived from this study: PubMed 39909709Barad A, Xu Y, Bender E, Kang W, Xu R, Gu Z, Pressman EK, O'Brien KO. Characterization of iron status biomarkers and hematological indices among young adults of East Asian or Northern European ancestry: A cross-sectional analysis from the Iron Genes in East Asian and Northern European Adults Study (FeGenes). Am J Clin Nutr. 2025 Feb;121(2):394-405. doi: 10.1016/j.ajcnut.2024.10.014.
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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. This study is not recruiting at the moment.
Kimberly O O'Brien principal investigator
Cornell University
2 sites in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Anemia, Iron Deficiency and Iron Overload, run by Cornell University at 2 sites in United States.
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 7 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: under way, not looking for participants, as of the sponsor's last update on 23 Oct 2026. Status can change between updates, so confirm with the study contact before making plans.
Where is the study taking place?
The record lists 2 sites in United States. 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?
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?
The percent of non-heme iron absorption (time frame: 2-week). The study lists 5 primary outcomes in all. It is what the study was designed to measure, not a finding.
Where can I read the original study information?
On the ClinicalTrials.gov record for NCT04198545, which also lists 6 linked publications.
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 23 Oct 2026.