CClinicalTrials.gg
Sign In
CompletedNCT05105438Updated Jan 24, 2024

Alternate Day vs. Daily Iron Supplementation in Iron Depleted Women

An interventional study of Consecutive Day Dosing and Alternate Day Dosing in Iron-deficiency and Iron Deficiency Anemia, sponsored by Swiss Federal Institute of Technology. Completed at 1 site in Switzerland. Open to female participants aged 18 Years to 45 Years, including healthy volunteers. Per ClinicalTrials.gov, last updated 2024-01-24.

Sponsored by Swiss Federal Institute of Technology · Not applicable, Interventional, and Treatment

Phase
Not applicable
Study type
Interventional
Enrollment
150
Allocation
Randomized
Ages
18 Years to 45 Years
Sex
Female
01

Study summary

Iron deficiency (ID) with or without anemia is a major public health problem worldwide, especially in women of reproductive age. Iron supplementation can be an effective strategy to prevent and treat ID and iron deficiency anemia (IDA). Recent studies suggests that giving oral iron every other day would be an optimized dosing regimen with maximized absorption and a lower incidence of gastrointestinal side effects compared to consecutive day dosing. Long-term trials in which participants and investigators are blinded to the dosing interval with iron status and gastrointestinal side effects as study outcomes are needed.

02

Conditions studied

  • Iron-deficiency
  • Iron Deficiency Anemia

Keywords

  • iron supplementation
  • dosing regimen
  • iron sulfate
  • women of reproductive age
03

In context

Anemia

1,733 studies on the registry are indexed under Anemia; 246 are open to participants now.

This study's enrollment of 150 is above the median of 94 across 1,291 interventional studies indexed under Anemia.

Browse Anemia studies →

Lead sponsor

Swiss Federal Institute of Technology is the lead sponsor of 152 studies on the registry; 10 are open to participants now.

Counted across the registry records on this site, refreshed daily.

04

Who can participate

Ages eligible
18 Years to 45 Years
Sexes eligible
Female
Accepts healthy volunteers
Yes

Inclusion criteria

  • Female, 18 to 45 years old,
  • SF levels \<25 μg/L,
  • Hb levels ≥ 11 g/dL
  • Normal Body Mass Index (18.5-25 kg/m2),
  • In possession of a mobile phone on which the study app can be loaded,
  • Signed informed consent,
  • Not mandatory (only for subgroup analysis): having participated in a former stable iron isotope study in our laboratory between 1-5 y ago

Exclusion criteria

Exclusion Criteria:

  • Elevated CRP > 5 mg/L,
  • Any metabolic, gastrointestinal, kidney or chronic disease (self-reported) affecting iron metabolism,
  • Continuous/long-term use of medication, which may interfere with iron absorption, gut physiology and iron metabolism,
  • Consumption of additional iron supplements over the study period,
  • Consumption of iron supplements since screening,
  • Difficulties with blood sampling,
  • Known hypersensitivity or allergy to iron or placebo capsules in the given amount (ferrous sulfate, mannitol, silica)
  • Pregnancy, breastfeeding
  • Women who intend to become pregnant during the course of the study,
  • Known or suspected non-compliance, drug or alcohol (more than 2 drinks/day) abuse,
  • Smokers (> 1 cigarette per week),
  • Participant is likely to be absent on one the study appointments,
  • Inability to follow the procedures of the study, e.g. due to language problems, self-reported psychological disorders, etc. of the participant.
05

Study design

Phase
Not applicable
Primary purpose
Treatment
Allocation
Randomized
Intervention model
Parallel assignment
Masking
Double (Participant, Investigator)
Enrollment
150 participants (actual)

Study arms

  • Active comparator
    Consecutive Day Dosing

    100 mg iron as FeSO4 daily for 3 months, followed by matched placebo daily for 3 months.

    Dietary Supplement: Consecutive Day Dosing

  • Experimental
    Alternate Day Dosing

    100 mg iron as FeSO4 and matched placebo on alternating days for 6 months.

    Dietary Supplement: Alternate Day Dosing

Interventions

  • Dietary supplementConsecutive Day Dosing

    100 mg iron as FeSO4 daily for 3 months, followed by matched placebo daily for 3 months.

  • Dietary supplementAlternate Day Dosing

    100 mg iron as FeSO4 and matched placebo on alternating days for 6 months.

06

What researchers measure

Primary outcomes

  1. Serum Ferritin (SF)

    in consecutive day group

    Time frame: Day 93

  2. Serum Ferritin (SF)

    in alternate day group

    Time frame: Day 186

  3. Event rate of GI side effects

    in consecutive day group

    Time frame: Day 90

  4. Event rate of GI side effects

    in alternate day group

    Time frame: Day 183

Secondary outcomes

  1. Hemoglobin (Hb)

    Time frame: Day 0

  2. Hemoglobin (Hb)

    Time frame: Day 46

  3. Hemoglobin (Hb)

    Time frame: Day 90

  4. Hemoglobin (Hb)

    Time frame: Day 139

  5. Hemoglobin (Hb)

    Time frame: Day 183

  6. Serum Ferritin (SF)

    Time frame: Day 0

  7. Serum Ferritin (SF)

    Time frame: Day 46

  8. Serum Ferritin (SF)

    Time frame: Day 93

  9. Serum Ferritin (SF)

    Time frame: Day 139

  10. Serum Ferritin (SF)

    Time frame: Day 186

  11. Serum Transferrin Receptor (sTfR)

    Time frame: Day 0

  12. Serum Transferrin Receptor (sTfR)

    Time frame: Day 46

  13. Serum Transferrin Receptor (sTfR)

    Time frame: Day 93

  14. Serum Transferrin Receptor (sTfR)

    Time frame: Day 139

  15. Serum Transferrin Receptor (sTfR)

    Time frame: Day 186

  16. Total iron binding capacity (TIBC)

    Time frame: Day 0

  17. Total iron binding capacity (TIBC)

    Time frame: Day 93

  18. Total iron binding capacity (TIBC)

    Time frame: Day 186

  19. Serum Iron (SFe)

    Time frame: Day 0

  20. Serum Iron (SFe)

    Time frame: Day 93

  21. Serum Iron (SFe)

    Time frame: Day 186

  22. C-Reactive Protein (CRP)

    Time frame: Day 0

  23. C-Reactive Protein (CRP)

    Time frame: Day 46

  24. C-Reactive Protein (CRP)

    Time frame: Day 93

  25. C-Reactive Protein (CRP)

    Time frame: Day 139

  26. C-Reactive Protein (CRP)

    Time frame: Day 186

  27. Alpha-1-acid Glycoprotein (AGP)

    Time frame: Day 0

  28. Alpha-1-acid Glycoprotein (AGP)

    Time frame: Day 46

  29. Alpha-1-acid Glycoprotein (AGP)

    Time frame: Day 93

  30. Alpha-1-acid Glycoprotein (AGP)

    Time frame: Day 139

  31. Alpha-1-acid Glycoprotein (AGP)

    Time frame: Day 186

  32. Intestinal Fatty Acid-binding Protein (I-FABP)

    Time frame: Day 0

  33. Intestinal Fatty Acid-binding Protein (I-FABP)

    Time frame: Day 90

  34. Intestinal Fatty Acid-binding Protein (I-FABP)

    Time frame: Day 183

  35. Calprotectin

    Time frame: Day 0

  36. Calprotectin

    Time frame: Day 90

  37. Calprotectin

    Time frame: Day 183

  38. Hepcidin

    Time frame: Day 0

  39. Hepcidin

    Time frame: Day 46

  40. Hepcidin

    Time frame: Day 90

  41. Hepcidin

    Time frame: Day 139

  42. Hepcidin

    Time frame: Day 183

  43. Event rate of GI side effects

    Time frame: Day 90

  44. Event rate of GI side effects

    Time frame: Day 183

  45. Incidence of GI side effects

    Time frame: Day 90

  46. Incidence of GI side effects

    Time frame: Day 183

  47. Event proportion of GI side effects

    Time frame: Day 90

  48. Event proportion of GI side effects

    Time frame: Day 183

  49. Severity of GI side effects

    Time frame: Day 90

  50. Severity of GI side effects

    Time frame: Day 183

  51. Fecal blood losses

    Time frame: Day 0

  52. Fecal blood losses

    Time frame: Day 90

  53. Fecal blood losses

    Time frame: Day 183

  54. Iron absorption from supplements

    Time frame: Day 90

  55. Iron absorption from supplements

    Time frame: Day 183

07

Study locations

1 site
  • ETH Zurich; Human Nutrition Laboratory; Institute of Food, Nutrition and Health
    Zürich, 8092, Switzerland
08

References and documents

Individual participant data

Plan to share: No

No publications or documents are linked to this record.

09

Updates

Tracking since Sep 25, 2026
No changes since tracking began. The registry record was last updated on Jan 24, 2024, before this site started recording changes on Sep 25, 2026. Its history is on ClinicalTrials.gov ↗
10

Registry details

Key details

Study ID
NCT05105438
Lead sponsor
Swiss Federal Institute of Technology
Responsible party
Jessica Rigutto (Dr., Swiss Federal Institute of Technology) — Principal investigator
First posted
Nov 3, 2021
Start date
Dec 16, 2021
Primary completion
Aug 10, 2022
Completion
Dec 8, 2022
Last update
Jan 24, 2024

Study contacts

Nicole Stoffel, Dr.
principal investigator · Human Nutrition Laboratory, ETH Zuerich

Oversight

Data monitoring committee
Yes
FDA-regulated drug
No
FDA-regulated device
No
View the source record on ClinicalTrials.gov ↗

Not currently enrolling

This study is completed, as verified in Jan 2024. You cannot join it, but the record below documents what was studied.

Follow this study

Get an email when the registry record changes — status, dates, results — or when someone posts here.

Sign in to follow

Discussion

Questions and observations about this study, from anyone following it. Not medical advice, and not a channel to the study team — their contact details are on the registry record.

Sign in to join the discussion. Reading takes no account; posting does. You choose a display name, and a pseudonym is the default.

Nothing here yet. If you are running this trial, taking part in it, or weighing whether to, this is the place to say so.

Other studies in this condition

Anemia→

Other studies from this sponsor

Swiss Federal Institute of Technology

Start the discussion