Alternative vs. Once-Daily Oral Iron Supplementation in Iron Deficiency Anemia (IDA)

January 5, 2026 updated by: Phramongkutklao College of Medicine and Hospital

Alternative vs. Once-Daily Oral Iron Supplementation in Iron Deficiency Anemia (IDA): A Multicenter, Randomized, Open-Label, Non-Inferiority Trial

The goal of this clinical trial is to compare the effectiveness and tolerability of two different oral iron regimens in adults with iron deficiency anemia (IDA). The main questions it aims to answer are:

Is alternate-day oral iron supplementation as effective as once-daily dosing in improving hemoglobin levels?

What are the side effects associated with each dosing regimen?

Researchers will compare once-daily vs. alternate-day oral ferrous fumarate to evaluate whether alternate-day dosing is non-inferior in terms of hematologic response, with fewer adverse effects.

Participants will:

Be randomly assigned to take ferrous fumarate 200 mg once daily or 400 mg on alternate days for 8 weeks

Undergo blood tests and clinical assessments at baseline, Week 4, and Week 8

Report any side effects and bring remaining pills to evaluate medication adherence

This is a multicenter, randomized, open-label, non-inferiority trial conducted in adults aged 20 years or older with IDA.

Study Overview

Status

Status

Indicates the current recruitment status or the expanded access status.
Recruiting

Conditions

Conditions

The disease, disorder, syndrome, illness, or injury that is being studied. On ClinicalTrials.gov, conditions may also include other health-related issues, such as lifespan, quality of life, and health risks.

Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.

Study Type

Study Type

Describes the nature of a clinical study. Study types include interventional studies (also called clinical trials), observational studies (including patient registries), and expanded access.
Interventional

Enrollment (Estimated)

Enrollment

The number of participants in a clinical study. The "anticipated" enrollment is the target number of participants that the researchers need for the study.
114

Phase

Phase

The stage of a clinical trial studying a drug or biological product, based on definitions developed by the U.S. Food and Drug Administration (FDA). The phase is based on the study's objective, the number of participants, and other characteristics. There are five phases: Early Phase 1 (formerly listed as Phase 0), Phase 1, Phase 2, Phase 3, and Phase 4. Not Applicable is used to describe trials without FDA-defined phases, including trials of devices or behavioral interventions.
  • Not Applicable

Contacts and Locations

This section provides the contact details for those conducting the study, and information on where this study is being conducted.

Study Contact

Study Contact

The name and contact information for the person who can answer enrollment questions for a clinical study. Each location where the study is being conducted may also have a specific contact, who may be better able to answer those questions.

Study Contact Backup

Study Locations

  • Thailand
      • Bangkok, Thailand, 10400
        • Recruiting
        • Phramongkutklao Hospital
        • Contact:
        • Contact:
        • Principal Investigator:
          • Aticha Kraiput, Doctor of Medicine
        • Sub-Investigator:
          • Tanapun Thamgrang, Doctor of Medicine

Participation Criteria

Researchers look for people who fit a certain description, called eligibility criteria. Some examples of these criteria are a person's general health condition or prior treatments.

Eligibility Criteria

Eligibility Criteria

The key requirements that people who want to participate in a clinical study must meet or the characteristics they must have. Eligibility criteria consist of both inclusion criteria (which are required for a person to participate in the study) and exclusion criteria (which prevent a person from participating). Types of eligibility criteria include whether a study accepts healthy volunteers, has age or age group requirements, or is limited by sex.

Ages Eligible for Study

  • Adult
  • Older Adult

Accepts Healthy Volunteers

No

Description

Inclusion Criteria:

  • Male or female patients aged ≥20 years diagnosed with iron deficiency anemia, defined as: hemoglobin (Hb) <13 g/dL in males or <12 g/dL in females, and ferritin <50 ng/mL or transferrin saturation (TSAT) <20%.
  • No iron supplementation within the past 3 months.

Exclusion Criteria:

  • Hemodynamic instability (e.g., acute bleeding or hypotension).
  • Severe heart failure (New York Heart Association [NYHA] Class III-IV) or other active cardiac diseases.
  • Active malignancy or history of cancer within the past 3 years (except non-melanoma skin cancer).
  • Pregnancy or breastfeeding.
  • Chronic liver disease including cirrhosis (Child-Pugh class B or C).
  • Chronic kidney disease (estimated glomerular filtration rate [eGFR] <60 mL/min/1.73 m²).
  • Clinically significant thalassemia or hemoglobinopathies.
  • Ongoing infection or chronic inflammatory diseases (e.g., rheumatoid arthritis, inflammatory bowel disease).
  • Malabsorption disorders (e.g., history of bariatric surgery).
  • Red blood cell transfusion within the past 3 months.

Withdrawal Criteria

  • Withdrawal of informed consent.
  • Severe adverse events requiring permanent discontinuation of study medication.
  • Investigator's judgment that continued participation poses a safety risk.
  • Non-adherence to study medication (compliance < 75%).

Treatment Failure

- Increase in hemoglobin level of < 1 g/dL at Week 4 or Week 8 compared with baseline.

Study Plan

This section provides details of the study plan, including how the study is designed and what the study is measuring.

How is the study designed?

Design Details

  • Primary Purpose: Treatment
  • Allocation: Randomized
  • Interventional Model: Parallel Assignment
  • Masking: None (Open Label)

Arms and Interventions

Participant Group / Arm

Participant Group / Arm

A group or subgroup of participants in a clinical trial that receives a specific intervention/treatment, or no intervention, according to the trial's protocol.
Intervention / Treatment

Intervention / Treatment

A process or action that is the focus of a clinical study. Interventions include drugs, medical devices, procedures, vaccines, and other products that are either investigational or already available. Interventions can also include noninvasive approaches, such as education or modifying diet and exercise.
Active Comparator: Once-Daily Dosing Group
Participants will receive ferrous fumarate 200 mg, taken orally once daily for 8 weeks. This arm represents the standard dosing regimen for treating iron deficiency anemia (IDA). Participants will be monitored at baseline, Week 4, and Week 8 for blood counts, iron parameters, and adverse effects. Medication adherence will be assessed using pill counts.
Drug: Ferrous Fumarate Oral Tablet
Ferrous fumarate oral tablet 200 mg is an iron supplement used for the treatment of iron deficiency anemia (IDA). In this study, it is administered as either one tablet daily (OD group) or two tablets on alternate days (AD group), with a treatment duration of 8 weeks. The goal is to compare the efficacy and tolerability of alternate-day dosing versus standard once-daily dosing.
Other Names:
  • Ferrous Fumarate 200 mg tablet
  • Oral iron supplement
Experimental: Alternate-Day Dosing Group
Participants will receive ferrous fumarate 400 mg (two 200 mg tablets), taken orally on alternate days for 8 weeks. This dosing strategy is being evaluated for improved iron absorption and fewer gastrointestinal side effects compared to daily dosing. Participants will be monitored at baseline, Week 4, and Week 8 for blood counts, iron parameters, and adverse effects. Medication adherence will be assessed using pill counts.
Drug: Ferrous Fumarate Oral Tablet
Ferrous fumarate oral tablet 200 mg is an iron supplement used for the treatment of iron deficiency anemia (IDA). In this study, it is administered as either one tablet daily (OD group) or two tablets on alternate days (AD group), with a treatment duration of 8 weeks. The goal is to compare the efficacy and tolerability of alternate-day dosing versus standard once-daily dosing.
Other Names:
  • Ferrous Fumarate 200 mg tablet
  • Oral iron supplement

What is the study measuring?

Primary Outcome Measures

Primary Outcome Measures

In a clinical study's protocol, the planned outcome measure that is the most important for evaluating the effect of an intervention/treatment. Most clinical studies have one primary outcome measure, but some have more than one.
Outcome Measure
Measure Description
Time Frame
Hemoglobin Level at Week 8 After Oral Iron Supplementation
Time Frame: 8 weeks
Hemoglobin concentration (g/dL) measured at Week 8 following oral ferrous fumarate supplementation. Participants are stratified by sex and baseline Hb level. Comparison between once-daily and alternate-day dosing groups will be analyzed using a linear mixed-effects model.
8 weeks

Secondary Outcome Measures

Secondary Outcome Measures

In a clinical study's protocol, a planned outcome measure that is not as important as the primary outcome measure for evaluating the effect of an intervention but is still of interest. Most clinical studies have more than one secondary outcome measure.
Outcome Measure
Measure Description
Time Frame
Change in Reticulocyte Count at Weeks 4 and 8
Time Frame: 4 and 8 weeks
Mean change in reticulocyte count (%) from baseline to Week 4 and Week 8.
4 and 8 weeks
Change in Serum Ferritin at Weeks 4 and 8
Time Frame: 4 and 8 weeks
Mean change in serum ferritin concentration (ng/mL) from baseline to Week 4 and Week 8.
4 and 8 weeks
Adverse Effects of Ferrous Fumarate
Time Frame: During the 8-week treatment period
Incidence and type of adverse effects experienced by participants during treatment with ferrous fumarate oral tablets.
During the 8-week treatment period

Collaborators and Investigators

This is where you will find people and organizations involved with this study.

Sponsor

Sponsor

The organization or person who initiates the study and who has authority and control over the study.
Phramongkutklao College of Medicine and Hospital

Study record dates

These dates track the progress of study record and summary results submissions to ClinicalTrials.gov. Study records and reported results are reviewed by the National Library of Medicine (NLM) to make sure they meet specific quality control standards before being posted on the public website.

Study Major Dates

Study Start (Actual)

Study Start

The actual date on which the first participant was enrolled in a clinical study. The "anticipated" study start date is the date that the researchers think will be the study start date.
June 9, 2025

Primary Completion (Estimated)

Primary Completion

The date on which the last participant in a clinical study was examined or received an intervention to collect final data for the primary outcome measure. Whether the clinical study ended according to the protocol or was terminated does not affect this date. For clinical studies with more than one primary outcome measure with different completion dates, this term refers to the date on which data collection is completed for all the primary outcome measures. The "anticipated" primary completion date is the date that the researchers think will be the primary completion date for the study.
December 31, 2027

Study Completion (Estimated)

Study Completion

The date on which the last participant in a clinical study was examined or received an intervention/treatment to collect final data for the primary outcome measures, secondary outcome measures, and adverse events (that is, the last participant's last visit). The "anticipated" study completion date is the date that the researchers think will be the study completion date.
December 31, 2027

Study Registration Dates

First Submitted

First Submitted

The date on which the study sponsor or investigator first submitted a study record to ClinicalTrials.gov. There is typically a delay of a few days between the first submitted date and the record's availability on ClinicalTrials.gov (the first posted date).
June 1, 2025

First Submitted That Met QC Criteria

First Submitted That Met QC Criteria

The date on which the study sponsor or investigator first submits a study record that is consistent with National Library of Medicine (NLM) quality control (QC) review criteria. The sponsor or investigator may need to revise and submit a study record one or more times before NLM's QC review criteria are met. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
June 10, 2025

First Posted (Actual)

First Posted

The date on which the study record was first available on ClinicalTrials.gov after National Library of Medicine (NLM) quality control (QC) review has concluded. There is typically a delay of a few days between the date the study sponsor or investigator submitted the study record and the first posted date.
June 11, 2025

Study Record Updates

Last Update Posted (Actual)

Last Update Posted

The most recent date on which changes to a study record were made available on ClinicalTrials.gov. There may be a delay between when the changes were submitted to ClinicalTrials.gov by the study's sponsor or investigator (the last update submitted date) and the last update posted date.
January 7, 2026

Last Update Submitted That Met QC Criteria

Last Update Submitted That Met QC Criteria

The most recent date on which the study sponsor or investigator submitted changes to a study record that are consistent with National Library of Medicine (NLM) quality control (QC) review criteria. It is the responsibility of the sponsor or investigator to ensure that the study record is consistent with the NLM QC review criteria.
January 5, 2026

Last Verified

Last Verified

The most recent date on which the study sponsor or investigator confirmed the information about a clinical study on ClinicalTrials.gov as accurate and current. If a study with a recruitment status of recruiting; not yet recruiting; or active, not recruiting has not been confirmed within the past 2 years, the study's recruitment status is shown as unknown.
January 1, 2026

More Information

Terms related to this study

Keywords

Additional Relevant MeSH Terms

Other Study ID Numbers

Other Study ID Numbers

Identifiers or ID numbers other than the NCT number that are assigned to a clinical study by the study's sponsor, funders, or others. These numbers may include unique identifiers from other trial registries and National Institutes of Health grant numbers.
  • Hemato-001

Plan for Individual participant data (IPD)

Plan to Share Individual Participant Data (IPD)?

NO

IPD Plan Description

Individual participant data (IPD) will not be shared due to institutional policy and privacy concerns. Only aggregate data may be shared upon reasonable request.

Drug and device information, study documents

Studies a U.S. FDA-regulated drug product

No

Studies a U.S. FDA-regulated device product

No

This information was retrieved directly from the website clinicaltrials.gov without any changes. If you have any requests to change, remove or update your study details, please contact register@clinicaltrials.gov. As soon as a change is implemented on clinicaltrials.gov, this will be updated automatically on our website as well.

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