Obesity & OverweightNCT07855939
Long-term Iron Absorption and Loss in Women
An observational study of Obesity & Overweight and Normal Weight Adults, run by Mahidol University at 1 site in Thailand.
Trial summary
Obese people typically have chronic low-grade inflammation. Based on short-term studies, this inflammation could affect the absorption, utilization, storage, and mobilization of iron, and individuals with inflammation might develop iron deficiency (ID) and anemia when inadequacy of iron intake is presented. Read more about this study
- Who is it for?
- Ages 40 to 50 years, women onlyHealthy volunteers can take part
- Conditions the study is for
- Obesity & Overweight, Normal Weight Adults
- How many people
- 64 participants
- Where
- 1 siteThailand
- Study dates
- 8 May 2025to 31 Aug 2028
- How long will I take part?
- 18 Months
- 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 40 to 50 years
- Women only
- Healthy volunteers accepted
- Adult
Study population: The study population will consist of 64 women aged 40-50 years, divided into two groups: 32 participants who are overweight or obese, and 32 participants with normal weight.
Who may be able to join
- Normal weight group
- Aged 40-50 years
- Normal weight (BMI 18.5-22.9 kg/m²)
- Hb ≥12.0 g/dL and inflammation-adjusted SFa <50.0 µg/L
- CRP <5.0 mg/L
- Normal hemoglobin typing
Show all 14Show fewer
- Plans to reside in the study area for >2 years
- Overweight/obese group
- Aged 40-50 years
- Overweight or obese [Body Mass Index (BMI) ≥25.0 kg/m²] - the BMI cut-off follows the agreement of countries under the Coordinated Research Project (CRP) E43038 "Using the iron isotope dilution technique to assess the influence of inflammation on long-term iron absorption and loss," supported by the IAEA
- Hemoglobin (Hb) ≥12.0 g/dL and inflammation-adjusted serum ferritin (SFa) <50.0 µg/L
- C-reactive protein (CRP) between 5.0-25.0 mg/L
- Normal hemoglobin typing
- Plans to reside in the study area for >2 years
Who cannot join
- Normal weight group
- Having serious medical conditions such as cancer, chronic kidney disease, chronic liver disease, or chronic heart failure
- Having metabolic NCDs (e.g., diabetes, hyperlipidemia, hypertension) requiring hospitalization
- Pregnant, breastfeeding, or planning pregnancy during the study
- Chronic infectious disease (e.g., tuberculosis, AIDS)
- Regular use of anti-inflammatory or other medications (except contraceptives and acne medication)
Show all 23Show fewer
- Taking vitamin or mineral supplements during or within two weeks prior to the study
- Participating in a weight-loss program
- Known intolerance to iron supplements (e.g., vomiting, diarrhea, abdominal pain, bloating, nausea, or allergic reactions such as rash, breathing difficulty, chest tightness, facial or lip swelling)
- Blood transfusion, blood donation, or significant blood loss during the study or within 6 months before enrollment
- Heavy menstrual bleeding (>80 mL/day, calculated from menstrual record)
- Overweight/obese group
- Obesity class II (BMI ≥35.0 kg/m²) with high health risk
- Having serious medical conditions such as cancer, chronic kidney disease, chronic liver disease, or chronic heart failure
- Having metabolic noncommunicable diseases (e.g., diabetes, hyperlipidemia, hypertension) requiring hospitalization
- Pregnant, breastfeeding, or planning pregnancy during the study
- Chronic infectious disease (e.g., tuberculosis, AIDS)
- Regular use of anti-inflammatory or other medications (except contraceptives and acne medication)
- Taking vitamin or mineral supplements during or within two weeks prior to the study
- Participating in a weight-loss program
- Known intolerance to iron supplements (e.g., vomiting, diarrhea, abdominal pain, bloating, nausea, or allergic reactions such as rash, breathing difficulty, chest tightness, facial or lip swelling)
- Blood transfusion, blood donation, or significant blood loss during the study or within 6 months before enrollment
- Heavy menstrual bleeding (>80 mL/day, calculated from menstrual record)
Trial locations and contacts
1 site in 1 country. Contact the study team or a site near you to ask about taking part.
Aree Prachansuwan, Ph.D. contact
Thailand1 site, 1 recruiting
- Recruiting
Institute of Nutrition
Nakhon Pathom, 73170
Tippawan Pongcharoen, Ph.D., 0813749901, tippawan.pon@mahidol.ac.th
Aree Prachansuwan, Ph.D., +890060602, aree.prc@mahidol.ac.th
About this study
Official title: Long-term Iron Absorption and Loss in Overweight/Obese Thai Middle-aged Women
Obese people typically have chronic low-grade inflammation. Based on short-term studies, this inflammation could affect the absorption, utilization, storage, and mobilization of iron, and individuals with inflammation might develop iron deficiency (ID) and anemia when inadequacy of iron intake is presented. The double burden of malnutrition is nowadays emerging as a major public health concern in many countries, including Thailand. Understanding the association of chronic inflammation among people with overweight or obesity (OW/OB) with long-term iron absorption and loss is important for developing appropriate policies and programs to promote iron balance and, consequently, optimal iron status and health outcomes. Since previous reports among Thai women showed a high prevalence of OW/OB and anemia, this study will be conducted to determine the long-term iron absorption and loss among OW/OB free-living women using the iron isotope dilution method.
Read the detailed description
- Research Objective To study iron absorption, loss, and long-term iron gain in overweight or obese middle-aged Thai women compared with normal-weight middle-aged Thai women.
- Research Methodology 2.1 Study design: This study is a longitudinal study comparing long-term iron absorption and loss between overweight or obese middle-aged Thai women and normal-weight middle-aged Thai women.
2.2 Study population: The study population consists of 64 women aged 40-50 years, divided into two groups: 32 overweight or obese women, and 32 normal-weight women.
2.3 Research Procedures 2.3.1 Before data collection: The research protocol is submitted for approval to the Central Institutional Review Board, Mahidol University. All data collectors will be trained prior to fieldwork. Upon receiving ethical approval, recruitment posters will be used to invite participants.
Screening process:
- Interested individuals meeting preliminary eligibility criteria will be informed about study details, sign informed consent, and schedule the first visit for screening and blood collection.
- Visit 1 (Screening):
- Collect demographic and health history, measure weight, height, and body composition.
- Collect 5 mL blood sample for Hb, SF, CRP, AGP, and hemoglobin typing.
- Perform urine pregnancy test.
- Administer one 400 mg albendazole tablet to prevent parasitic infection.
Iron isotope administration and follow-up:
2.3.2 Eligible participants will return within 1-2 weeks for the second visit.
Visit 2 (Month 0; M0):
Participants will consume a 15 mg ⁵⁷Fe isotope solution followed by 100 mg vitamin C drink, then fast for 3 hours.
A snack (plain yogurt and water) will be provided 1.5 hours after ingestion. A 24-hour dietary recall and semi-quantitative food frequency questionnaire (FFQ) will be conducted, with two additional 24-hour recalls by phone (2 weekdays and 1 weekend day).
Participants will then enter a 1-year equilibration period, recording illness and menstrual data monthly. The research team will monitor via LINE or email.
Visit 3 (Month 9; M9):
Collect fasting blood (5 mL) for Hb, glucose, HbA1c, and lipid profile; measure weight, BP, and conduct 24-hour recall (plus two by phone).
Visit 4 (After 1 year; WK0):
Collect fasting blood (10 mL) for Hb, SF, TfR, CRP, AGP, erythrocyte isotopic enrichment.
Measure weight, body composition, pregnancy test, and dietary recalls (3 days) and FFQ.
Visits 5-7 (WK8, WK16, WK24):
For eligible participants, repeat blood tests (7 mL) for Hb, SF, TfR, CRP, AGP, isotopic enrichment, anthropometry, pregnancy test, 3-day dietary recalls, and FFQ.
2.4 Research Instruments
- General information and medical history questionnaire, 24-hour dietary recall, and FFQ.
- Illness and menstrual record forms.
- Anthropometry and clinical measures:
- Weight: InBody digital scale
- Height: Harpenden stadiometer
- Body composition: Bioelectrical Impedance Analyzer (BIA; InBody)
- Blood pressure: Omron digital sphygmomanometer
- Laboratory analyses:
- Hb: Complete Blood Count (CBC) using flow cytometry
- SF, TfR, CRP, AGP: ELISA (SFa calculated from SF, CRP, AGP)
- Hemoglobin typing: Capillary electrophoresis
- Fasting glucose: Enzymatic method
- HbA1c: Turbidimetric inhibition immunoassay
- Lipids: Enzymatic colorimetric and homogeneous methods
- Iron isotopes: Inductively Coupled Plasma Mass Spectrometry (ICP-MS) 2.5 Data Analysis Nutrient intake (energy, carbohydrate, protein, fat, iron, zinc, calcium, vitamin C, vitamin A, and fiber) will be calculated using INMUCAL software.
Dietary patterns will be analyzed using Principal Component Analysis (PCA).
The average iron absorption (Fe_abs) over the study period will be calculated as:
Feabs=kabs×FetotalFe_{abs} = k_{abs} \times Fe_{total}Feabs=kabs×Fetotal where Fe_total is the total body iron at the midpoint estimated from the regression of Fe_total over time, and k_abs is the fractional iron absorption rate derived from the slope of the regression line of ln(⁵⁷Fe) vs. time.
Average iron loss (Fe_loss) is calculated similarly:
Feloss=kloss×FetotalFe_{loss} = k_{loss} \times Fe_{total}Feloss=kloss×Fetotal
Iron gain (Fe_gain) is calculated as:
Fegain=Feabs-FelossFe_{gain} = Fe_{abs} - Fe_{loss}Fegain=Feabs-Feloss Differences between groups in general characteristics, biochemical parameters, and iron absorption/loss slopes will be tested using Independent t-test or Mann-Whitney U-test, as appropriate.
A Linear Mixed-Effects Model will be used to analyze group differences in longitudinal changes of iron absorption, loss, and gain.
Statistical significance will be set at p < 0.05.
- Conditions
- Obesity & Overweight, Normal Weight Adults
- Keywords
- low-grade chronic inflammation, long-term iron absorption and loss, Iron isotope
- Medical subject headings
- Obesity, Overweight
What participants receive
What participants receive. In a randomised study each person is assigned to one group by chance.
| Study group | Role | What they receive |
|---|---|---|
| Normal weight | BMI 18.5-22.9 kg/m2 | |
| Overweight or obesity | BMI 25-35 kg/m2 |
What is being measured
The primary outcome is the main question the study is designed to answer.
Mean long-term iron absorption (Fe abs)
Calculated over the duration of the study as follows: Fe abs = k abs x Fe total Where Fe total is the total body iron at the midpoint, calculated from the linear regression of Fe total versus time across each measurement point; and k abs is the fraction of total body iron absorbed per unit of time (derived from the slope of the linear regression equation of ln 57 Fe versus time).
57 Fe isotope will be measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
Measured: Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24).
Mean long-term iron loss (Fe loss)
Calculated in the same manner as iron absorption: Fe loss = k loss x Fe total Where k loss is the fraction of total body iron lost per unit of time.
Measured: Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Iron gain (Fe gain)
Calculated as net iron balance: Fe gain = Fe abs - Fe loss
Measured: Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Secondary outcomes (14)
Weight (kg)
Weight will be measured in kg (to the nearest 0.1 kg) using an Inbody digital weighing scale.
Measured: Visit 1 (Screening), Visit 3 (Month 9), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Height (cm)
Height will be measured to the mearest 0.1 cm using a Harpenden stadiometer.
Measured: Visit 1 (Screening)
Body Mass Index (BMI, kg/m²)
BMI will be calculatedn body weight in kilograms divided by height in meters squared.
Measured: Visit 1 (Screening), Visit 3 (Month 9), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Body composition (fat mass)
Body composition (fat mass) will be measured using the Bioelectrical Impedance Analyzer (BIA; InBody).
Measured: Visit 1 (Screening), Visit 4 (after 1 year; WK0), Visits 7 (WK24)
Nutrient intakes
Nutrient intakes (energy, carbohydrate, protein, fat, iron, zinc, calcium, vitamin C, vitamin A, and fiber) will be calculated from 3-day 24-hr dietary recalls using INMUCAL software.
Measured: Visit 2 (Month 0), Visit 3 (Month 9), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Dietary pattern
Dietary patern from FFQ will be analyzed using the Principal Component Analysis (PCA)
Measured: Visit 2 (Month 0), Visit 4 (after 1 year; WK0), Visits 7 (WK24)
Hemoglobin (Hb, g/L)
Hb concentration will be assessed using flow cytometry
Measured: Visit 1 (Screening), Visit 3 (Month 9), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Serum ferritin (SF, µg/L)
SF will be measured using Enzyme-linked immunosorbent assay (ELISA)
Measured: Visit 1 (Screening), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
serum transferrin receptor (sTfR µg/L)
sTfR will be assessed using ELISA
Measured: Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
c-reactive protein (CRP, mg/L)
CRP will measured using ELISA
Measured: Visit 1 (Screening), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
alpha-1 acid glycoprotein (AGP, g/L)
AGP will be measured using ELISA
Measured: Visit 1 (Screening), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Glycated hemoglobin (HbA1c, %)
HbA1c wil be measured by Turbidimetric inhibition immunoassay
Measured: Visit 3 (Month 9)
Lipid profile
Lipid profile (total cholesterol, LDL-cholesterol, HDL-cholesterol, triglycerides) will be measured using Enzymatic colorimetric and homogeneous methods.
Measured: Visit 3 (Month 9)
Blood pressure (BP, mmHg)
BP will be measured using Omron digital sphygmomanometer
Measured: Visit 3 (Month 9)
Timeline
From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.
- First posted2 Oct 2026
- Study start8 May 2025
- Primary completion31 Dec 2027 (estimated)
- Study completion31 Aug 2028 (estimated)
Resources
- Official record on ClinicalTrials.govThe registry entry this page is built from, with its full change history.
- Publications (8)Papers the sponsor has linked to this study.
- Other trials for Obesity & OverweightStudies of the same condition, open and under way.
- More trials run by Mahidol UniversityThe sponsor's other registered studies.
- 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
- Cohort
- Time perspective
- Prospective
- Enrolment
- 64 participants (estimated)
- Target duration
- 18 Months
Sponsor and investigators
- Lead sponsor
- Mahidol University
- Sponsor type
- University, hospital or other
- Collaborators
- International Atomic Energy Agency
- Responsible party
- Principal investigator, Tippawan Pongcharoen, Mahidol University
- Investigators
- Veronica LOPEZ TEROS, Ph.D., Study director, Internation Atomic Energy Agency
IDs, dates and publications
- ClinicalTrials.gov ID
- NCT07855939
- Sponsor's protocol ID
- C00NU66050024
- Status last verified
- Sep 2026
- First submitted
- 6 Aug 2026
- Last updated
- 2 Oct 2026
- Results posted
- No
- FDA-regulated drug
- No
- FDA-regulated device
- No
- Individual data sharing
- Undecided: There has been ongoing discussion regarding collaboration on data analysis and publication among countries that have conducted studies supported by the International Atomic Energy Agency (IAEA).
Publications
International Atomic Energy Agency (IAEA). Assessment of iron bioavailability in humans using stable iron isotope techniques. IAEA Human Health Series No.21, Vienna 2021. Available at https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1544_web.pdf.
Stoffel NU, Cercamondi CI, Brittenham G, Zeder C, Geurts-Moespot AJ, Swinkels DW, Moretti D, Zimmermann MB. Iron absorption from oral iron supplements given on consecutive versus alternate days and as single morning doses versus twice-daily split dosing in iron-depleted women: two open-label, randomised controlled trials. Lancet Haematol. 2017 Nov;4(11):e524-e533. doi: 10.1016/S2352-3026(17)30182-5. Epub 2017 Oct 9.
PubMed 29032957Speich C, Mitchikpe CES, Cercamondi CI, Zeder C, Brittenham GM, Moretti D, Zimmermann MB. Direct assessment of body iron balance in women with and without iron supplementation using a long-term isotope dilution method in Benin and Switzerland. Am J Clin Nutr. 2021 Jun 1;113(6):1657-1669. doi: 10.1093/ajcn/nqaa433.
PubMed 33693464Zimmermann MB, Zeder C, Muthayya S, Winichagoon P, Chaouki N, Aeberli I, Hurrell RF. Adiposity in women and children from transition countries predicts decreased iron absorption, iron deficiency and a reduced response to iron fortification. Int J Obes (Lond). 2008 Jul;32(7):1098-104. doi: 10.1038/ijo.2008.43. Epub 2008 Apr 22.
PubMed 18427564Luciani N, Brasse-Lagnel C, Poli M, Anty R, Lesueur C, Cormont M, Laquerriere A, Folope V, LeMarchand-Brustel Y, Gugenheim J, Gual P, Tran A, Bekri S. Hemojuvelin: a new link between obesity and iron homeostasis. Obesity (Silver Spring). 2011 Aug;19(8):1545-51. doi: 10.1038/oby.2011.12. Epub 2011 Feb 10.
PubMed 21311510Cepeda-Lopez AC, Aeberli I, Zimmermann MB. Does obesity increase risk for iron deficiency? A review of the literature and the potential mechanisms. Int J Vitam Nutr Res. 2010 Oct;80(4-5):263-70. doi: 10.1024/0300-9831/a000033.
PubMed 21462109Cepeda-Lopez AC, Osendarp SJ, Melse-Boonstra A, Aeberli I, Gonzalez-Salazar F, Feskens E, Villalpando S, Zimmermann MB. Sharply higher rates of iron deficiency in obese Mexican women and children are predicted by obesity-related inflammation rather than by differences in dietary iron intake. Am J Clin Nutr. 2011 May;93(5):975-83. doi: 10.3945/ajcn.110.005439. Epub 2011 Mar 16.
PubMed 21411619Gonzalez-Dominguez A, Visiedo-Garcia FM, Dominguez-Riscart J, Gonzalez-Dominguez R, Mateos RM, Lechuga-Sancho AM. Iron Metabolism in Obesity and Metabolic Syndrome. Int J Mol Sci. 2020 Aug 1;21(15):5529. doi: 10.3390/ijms21155529.
PubMed 32752277
Study at a glance
From the registry record, last updated by the sponsor on 2 Oct 2026. Recruitment status is as the sponsor reported it: confirm with the study team.
- Official title
- Long-term Iron Absorption and Loss in Overweight/Obese Thai Middle-aged Women
- ClinicalTrials.gov ID
- NCT07855939
- Acronym / sponsor ID
- C00NU66050024
- Conditions
- Obesity & Overweight, Normal Weight Adults
- Keywords
- low-grade chronic inflammation, long-term iron absorption and loss, Iron isotope
- Study type
- Observational
- Recruitment status
- Recruiting
- Enrolment
- 64 participants (estimated)
- Lead sponsor
- Mahidol UniversityUniversity, hospital or other
- Collaborators
- International Atomic Energy Agency
- Study start
- 8 May 2025 (actual)
- Primary completion
- 31 Dec 2027 (estimated)
- Study completion
- 31 Aug 2028 (estimated)
- First posted
- 2 Oct 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.
Obese people typically have chronic low-grade inflammation. Based on short-term studies, this inflammation could affect the absorption, utilization, storage, and mobilization of iron, and individuals with inflammation might develop iron deficiency (ID) and anemia when inadequacy of iron intake is presented. The double burden of malnutrition is nowadays emerging as a major public health concern in many countries, including Thailand. Understanding the association of chronic inflammation among people with overweight or obesity (OW/OB) with long-term iron absorption and loss is important for developing appropriate policies and programs to promote iron balance and, consequently, optimal iron status and health outcomes. Since previous reports among Thai women showed a high prevalence of OW/OB and anemia, this study will be conducted to determine the long-term iron absorption and loss among OW/OB free-living women using the iron isotope dilution method.
Detailed description
- Research Objective To study iron absorption, loss, and long-term iron gain in overweight or obese middle-aged Thai women compared with normal-weight middle-aged Thai women.
- Research Methodology 2.1 Study design: This study is a longitudinal study comparing long-term iron absorption and loss between overweight or obese middle-aged Thai women and normal-weight middle-aged Thai women.
2.2 Study population: The study population consists of 64 women aged 40-50 years, divided into two groups: 32 overweight or obese women, and 32 normal-weight women.
2.3 Research Procedures 2.3.1 Before data collection: The research protocol is submitted for approval to the Central Institutional Review Board, Mahidol University. All data collectors will be trained prior to fieldwork. Upon receiving ethical approval, recruitment posters will be used to invite participants.
Screening process:
- Interested individuals meeting preliminary eligibility criteria will be informed about study details, sign informed consent, and schedule the first visit for screening and blood collection.
- Visit 1 (Screening):
- Collect demographic and health history, measure weight, height, and body composition.
- Collect 5 mL blood sample for Hb, SF, CRP, AGP, and hemoglobin typing.
- Perform urine pregnancy test.
- Administer one 400 mg albendazole tablet to prevent parasitic infection.
Iron isotope administration and follow-up:
2.3.2 Eligible participants will return within 1-2 weeks for the second visit.
Visit 2 (Month 0; M0):
Participants will consume a 15 mg ⁵⁷Fe isotope solution followed by 100 mg vitamin C drink, then fast for 3 hours.
A snack (plain yogurt and water) will be provided 1.5 hours after ingestion. A 24-hour dietary recall and semi-quantitative food frequency questionnaire (FFQ) will be conducted, with two additional 24-hour recalls by phone (2 weekdays and 1 weekend day).
Participants will then enter a 1-year equilibration period, recording illness and menstrual data monthly. The research team will monitor via LINE or email.
Visit 3 (Month 9; M9):
Collect fasting blood (5 mL) for Hb, glucose, HbA1c, and lipid profile; measure weight, BP, and conduct 24-hour recall (plus two by phone).
Visit 4 (After 1 year; WK0):
Collect fasting blood (10 mL) for Hb, SF, TfR, CRP, AGP, erythrocyte isotopic enrichment.
Measure weight, body composition, pregnancy test, and dietary recalls (3 days) and FFQ.
Visits 5-7 (WK8, WK16, WK24):
For eligible participants, repeat blood tests (7 mL) for Hb, SF, TfR, CRP, AGP, isotopic enrichment, anthropometry, pregnancy test, 3-day dietary recalls, and FFQ.
2.4 Research Instruments
- General information and medical history questionnaire, 24-hour dietary recall, and FFQ.
- Illness and menstrual record forms.
- Anthropometry and clinical measures:
- Weight: InBody digital scale
- Height: Harpenden stadiometer
- Body composition: Bioelectrical Impedance Analyzer (BIA; InBody)
- Blood pressure: Omron digital sphygmomanometer
- Laboratory analyses:
- Hb: Complete Blood Count (CBC) using flow cytometry
- SF, TfR, CRP, AGP: ELISA (SFa calculated from SF, CRP, AGP)
- Hemoglobin typing: Capillary electrophoresis
- Fasting glucose: Enzymatic method
- HbA1c: Turbidimetric inhibition immunoassay
- Lipids: Enzymatic colorimetric and homogeneous methods
- Iron isotopes: Inductively Coupled Plasma Mass Spectrometry (ICP-MS) 2.5 Data Analysis Nutrient intake (energy, carbohydrate, protein, fat, iron, zinc, calcium, vitamin C, vitamin A, and fiber) will be calculated using INMUCAL software.
Dietary patterns will be analyzed using Principal Component Analysis (PCA).
The average iron absorption (Fe_abs) over the study period will be calculated as:
Feabs=kabs×FetotalFe_{abs} = k_{abs} \times Fe_{total}Feabs=kabs×Fetotal where Fe_total is the total body iron at the midpoint estimated from the regression of Fe_total over time, and k_abs is the fractional iron absorption rate derived from the slope of the regression line of ln(⁵⁷Fe) vs. time.
Average iron loss (Fe_loss) is calculated similarly:
Feloss=kloss×FetotalFe_{loss} = k_{loss} \times Fe_{total}Feloss=kloss×Fetotal
Iron gain (Fe_gain) is calculated as:
Fegain=Feabs-FelossFe_{gain} = Fe_{abs} - Fe_{loss}Fegain=Feabs-Feloss Differences between groups in general characteristics, biochemical parameters, and iron absorption/loss slopes will be tested using Independent t-test or Mann-Whitney U-test, as appropriate.
A Linear Mixed-Effects Model will be used to analyze group differences in longitudinal changes of iron absorption, loss, and gain.
Statistical significance will be set at p < 0.05.
Study design
- Observational model
- Cohort
- Time perspective
- Prospective
- Target follow-up
- 18 Months
- Number of arms
- 2
| Arm | Type | Receives |
|---|---|---|
| Normal weight | – | –BMI 18.5-22.9 kg/m2 |
| Overweight or obesity | – | –BMI 25-35 kg/m2 |
Who may qualify
- Ages
- 40 to 50 years
- Sex
- Female only
- Healthy volunteers
- Accepted
- Age groups
- Adult
- Study population
- The study population will consist of 64 women aged 40-50 years, divided into two groups: 32 participants who are overweight or obese, and 32 participants with normal weight.
Key inclusion criteria (14 listed)
- Normal weight group
- Overweight/obese group
Key exclusion criteria (23 listed)
- Normal weight group
- Overweight/obese group
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
Mean long-term iron absorption (Fe abs)
Time frame: Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24).
Calculated over the duration of the study as follows: Fe abs = k abs x Fe total Where Fe total is the total body iron at the midpoint, calculated from the linear regression of Fe total versus time across each measurement point; and k abs is the fraction of total body iron absorbed per unit of time (derived from the slope of the linear regression equation of ln 57 Fe versus time). 57 Fe isotope will be measured using Inductively Coupled Plasma Mass Spectrometry (ICP-MS).
Mean long-term iron loss (Fe loss)
Time frame: Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Calculated in the same manner as iron absorption: Fe loss = k loss x Fe total Where k loss is the fraction of total body iron lost per unit of time.
Iron gain (Fe gain)
Time frame: Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Calculated as net iron balance: Fe gain = Fe abs - Fe loss
14 secondary outcomes
Weight (kg)
Time frame: Visit 1 (Screening), Visit 3 (Month 9), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Height (cm)
Time frame: Visit 1 (Screening)
Body Mass Index (BMI, kg/m²)
Time frame: Visit 1 (Screening), Visit 3 (Month 9), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Body composition (fat mass)
Time frame: Visit 1 (Screening), Visit 4 (after 1 year; WK0), Visits 7 (WK24)
Nutrient intakes
Time frame: Visit 2 (Month 0), Visit 3 (Month 9), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Dietary pattern
Time frame: Visit 2 (Month 0), Visit 4 (after 1 year; WK0), Visits 7 (WK24)
Hemoglobin (Hb, g/L)
Time frame: Visit 1 (Screening), Visit 3 (Month 9), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Serum ferritin (SF, µg/L)
Time frame: Visit 1 (Screening), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
serum transferrin receptor (sTfR µg/L)
Time frame: Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
c-reactive protein (CRP, mg/L)
Time frame: Visit 1 (Screening), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
alpha-1 acid glycoprotein (AGP, g/L)
Time frame: Visit 1 (Screening), Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24)
Glycated hemoglobin (HbA1c, %)
Time frame: Visit 3 (Month 9)
Lipid profile
Time frame: Visit 3 (Month 9)
Blood pressure (BP, mmHg)
Time frame: Visit 3 (Month 9)
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 2 Oct 2026.
- BackgroundInternational Atomic Energy Agency (IAEA). Assessment of iron bioavailability in humans using stable iron isotope techniques. IAEA Human Health Series No.21, Vienna 2021. Available at https://www-pub.iaea.org/MTCD/Publications/PDF/Pub1544_web.pdf.
- Background: PubMed 29032957Stoffel NU, Cercamondi CI, Brittenham G, Zeder C, Geurts-Moespot AJ, Swinkels DW, Moretti D, Zimmermann MB. Iron absorption from oral iron supplements given on consecutive versus alternate days and as single morning doses versus twice-daily split dosing in iron-depleted women: two open-label, randomised controlled trials. Lancet Haematol. 2017 Nov;4(11):e524-e533. doi: 10.1016/S2352-3026(17)30182-5. Epub 2017 Oct 9.
- Background: PubMed 33693464Speich C, Mitchikpe CES, Cercamondi CI, Zeder C, Brittenham GM, Moretti D, Zimmermann MB. Direct assessment of body iron balance in women with and without iron supplementation using a long-term isotope dilution method in Benin and Switzerland. Am J Clin Nutr. 2021 Jun 1;113(6):1657-1669. doi: 10.1093/ajcn/nqaa433.
- Background: PubMed 18427564Zimmermann MB, Zeder C, Muthayya S, Winichagoon P, Chaouki N, Aeberli I, Hurrell RF. Adiposity in women and children from transition countries predicts decreased iron absorption, iron deficiency and a reduced response to iron fortification. Int J Obes (Lond). 2008 Jul;32(7):1098-104. doi: 10.1038/ijo.2008.43. Epub 2008 Apr 22.
- Background: PubMed 21311510Luciani N, Brasse-Lagnel C, Poli M, Anty R, Lesueur C, Cormont M, Laquerriere A, Folope V, LeMarchand-Brustel Y, Gugenheim J, Gual P, Tran A, Bekri S. Hemojuvelin: a new link between obesity and iron homeostasis. Obesity (Silver Spring). 2011 Aug;19(8):1545-51. doi: 10.1038/oby.2011.12. Epub 2011 Feb 10.
- Background: PubMed 21462109Cepeda-Lopez AC, Aeberli I, Zimmermann MB. Does obesity increase risk for iron deficiency? A review of the literature and the potential mechanisms. Int J Vitam Nutr Res. 2010 Oct;80(4-5):263-70. doi: 10.1024/0300-9831/a000033.
- Background: PubMed 21411619Cepeda-Lopez AC, Osendarp SJ, Melse-Boonstra A, Aeberli I, Gonzalez-Salazar F, Feskens E, Villalpando S, Zimmermann MB. Sharply higher rates of iron deficiency in obese Mexican women and children are predicted by obesity-related inflammation rather than by differences in dietary iron intake. Am J Clin Nutr. 2011 May;93(5):975-83. doi: 10.3945/ajcn.110.005439. Epub 2011 Mar 16.
- Background: PubMed 32752277Gonzalez-Dominguez A, Visiedo-Garcia FM, Dominguez-Riscart J, Gonzalez-Dominguez R, Mateos RM, Lechuga-Sancho AM. Iron Metabolism in Obesity and Metabolic Syndrome. Int J Mol Sci. 2020 Aug 1;21(15):5529. doi: 10.3390/ijms21155529.
- Individual participant dataSharing planned: Undecided. There has been ongoing discussion regarding collaboration on data analysis and publication among countries that have conducted studies supported by the International Atomic Energy Agency (IAEA).
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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.
Aree Prachansuwan, Ph.D. contact
Veronica LOPEZ TEROS, Ph.D. study director
Internation Atomic Energy Agency
1 site in 1 country: see every site and its status.
Questions about this trial
What is this clinical trial studying?
An observational study of Obesity & Overweight and Normal Weight Adults, run by Mahidol University at 1 site in Thailand.
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 14 inclusion and 23 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 2 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 1 site in Thailand. 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 Tippawan Pongcharoen, Ph.D. (+66813749901, tippawan.pon@mahidol.ac.th), or a site near the patient. AzTrials does not enrol participants or take referrals.
What does the primary outcome measure?
Mean long-term iron absorption (Fe abs) (time frame: Visit 4 (after 1 year; WK0), Visits 5-7 (WK8, WK16, WK24).). The study lists 3 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 NCT07855939, which also lists 8 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 2 Oct 2026.