Potential Harms of Untargeted Iron Supplementation in Cambodia Where Iron Deficiency is Not the Cause of Anemia

NCT04017598 — Phase 4, Completed, 480 participants, University of British Columbia

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Is Iron Supplementation Harmful in Populations Where Iron Deficiency is Not the Cause of Anemia? A 12 Week Randomized Controlled Trial in Cambodia

RegistryNCT04017598
StatusCompleted
PhasePhase 4
Study typeInterventional; randomized, parallel, masking: quadruple, treatment
Enrollment480 (Actual)
SponsorUniversity of British Columbia (Other); collaborators: Helen Keller International, NCHADS - Ministry of Health of Cambodia, BC Children's Hospital Research Institute, The National Institute of Public Health Laboratory, Phnom Penh
ConditionsAnemia, Iron Deficiency, Anemia, Intestinal Inflammation, Inflammation, Intestine; Complaints
InterventionsFerrous sulfate, Ferrous Bisglycinate, Placebo of microcrystalline cellulose (Dietary supplement)
Datesstart 2019-12-10, primary completion 2020-05-30, completion 2023-12-01, first posted 2019-07-12, last updated 2024-05-08
Locations1 site in Cambodia

Related Papers Related Patents Related Grants Related Experts
All trials for Anemia, Iron Deficiency All trials for Anemia All trials of Ferrous sulfate All trials of Ferrous Bisglycinate

-Summary

In 2016, the World Health Organization (WHO) set a global policy recommending daily oral iron supplementation (60 mg iron) for 12 weeks for all women living in countries where anemia prevalence is >40%, such as in Cambodia. However, recent studies have shown the prevalence of iron deficiency to be low in Cambodian women and that supplementation would likely only benefit \~10% of women.

Iron supplementation may be harmful in women with genetic blood disorders (e.g. thalassemia), which are common in Cambodia, as these individuals are already at an increased risk of iron overload. The risks are made greater by the fact that iron absorption from most common form of supplementation, ferrous sulfate, is low. Typically less than 20% is absorbed in the gut; the remaining 80% passes unabsorbed into the colon where it can increase the risk of pathogen growth and gut inflammation. Alternatively, ferrous bisglycinate is a newer supplemental form of iron. This amino acid chelate has 2-4x higher bioavailability than ferrous sulfate and is associated with fewer GI side-effects.

In view of WHO policy and risks of supplementation, there is a need to determine the potential for harm, and if novel forms of iron supplements are safer.

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+Detailed description

The World Health Organization (WHO) set a Global Nutrition Target to reduce anemia in women of reproductive age by 50% by 2025. In 2016, the WHO implemented a global policy recommending oral iron supplementation (60 mg daily for 12 weeks) for all women where anemia prevalence is more than 40%, such as in Cambodia.

However, recent studies have shown the prevalence of iron deficiency to be low in Cambodian women. If iron deficiency is not the cause of anemia, then iron supplementation will not be effective at treating it. Further, iron supplementation may be harmful in some individuals, especially those with anemia caused by genetic blood disorders (which are common in Cambodia), as these individuals are already at an increased risk of iron overload. The risks are made greater by the fact that the type of iron that is commonly used in supplements (ferrous sulfate) is poorly absorbed. Typically, less than 20% is absorbed in the gut; the remaining 80% is unabsorbed in the colon where it can increase the risk of pathogen growth and gut inflammation.

To investigate the safety of untargeted iron supplementation, we will undertake a new study in Cambodia, where we will evaluate a newer type of iron supplement that may be absorbed better, and thus, safer than the conventional type. We will recruit non-pregnant women (18-45 years) and ask them to take one of the two forms of iron (ferrous sulfate or ferrous bisglycinate) or a placebo for 12 weeks (in line with the WHO global policy). We will measure hemoglobin and ferritin levels, which are markers of anemia and iron status, and markers of gut inflammation and gut pathogen abundance, before and after the intervention. This study will contribute to the evidence for safe and effective iron supplementation for women worldwide.

+Arms and interventions

ArmTypeInterventionsDescription
Ferrous SulfateActive comparatorDietary Supplement: Ferrous sulfateIron will be given orally in the form of tablets. A supplement of 60 mg will be taken daily for 12 weeks. World Health Organization standard dose and commonly used form of iron.
Ferrous BisglycinateExperimentalDietary Supplement: Ferrous BisglycinateIron will be given orally in the form of tablets. A supplement of 18 mg will be taken daily for 12 weeks. Ferrous bisglycinate has a bioavailability 2-4x greater than ferrous sulfate.
PlaceboPlacebo comparatorDietary Supplement: Placebo of microcrystalline cellulosePlacebo will be given orally in the form of tablets as a control made of microcrystalline cellulose.
  • Ferrous sulfate (Dietary supplement), also known as iron sulfate, ferrous sulphate, iron sulphate, Iron(II) sulfate: 60 mg elemental iron as ferrous sulfate
  • Ferrous Bisglycinate (Dietary supplement), also known as iron amino acid chelate, Iron glycinate, Bisglycine iron(II) salt, Iron(II) bisglycinate, Ferrous Bis-glycinate: 18 mg elemental iron as ferrous bisglycinate
  • Placebo of microcrystalline cellulose (Dietary supplement), also known as Control: placebo

+Outcome measures

Primary outcomes

  • Serum Ferritin [12 weeks]: Serum ferritin concentration (µg/l) at 12 weeks
  • Fecal calprotectin [12 weeks]: Fecal calprotectin concentration (mg/kg stool) at 12 weeks as a measure of gut inflammation.

Secondary outcomes

  • Gut pathogen abundance [12 weeks]: Real-time PCR nucleic acid amplification assay with an enteric bacterial panel.
  • Gut parasite abundance [12 weeks]: Real-time PCR nucleic acid amplification assay with an enteric parasite panel.
  • DNA damage [12 weeks]: DNA damage will be assessed by measuring DNA single-strand breaks, indicated by olive tail movement with use of alkali single-cell gel electrophoresis (Comet assay).
  • Alpha-1 acid glycoprotein (AGP, g/l) [12 weeks]
  • C-reactive protein (CRP, mg/l) [12 weeks]
  • Hemoglobin (g/L) [12 weeks]
  • Folate (ng/ml) [12 weeks]
  • Vitamin B12 (pmol/l) [12 weeks]

Other outcomes

  • Reported side effects [Continuous over 12 weeks]: (e.g., gastrointestinal pain) as a quality of life measure.
  • Genetic hemoglobinopathies [Baseline]: Genotyping to detect the presence of the most common hemoglobinopathies
  • Gut Pathogen abundance [12 weeks]: Whole metagenome shotgun 16S ribosomal RNA sequencing will be conducted on fecal samples, in order to validate the method against the established BD MAX panel in a subset of 150 women from our trial (50 from each study arm).

+Eligibility

Sex: Female, ages: 18 Years to 45 Years, accepts healthy volunteers

Inclusion Criteria:

* apparently healthy
* consent to participate in the study and provide blood, flocked rectal swab and stool samples
* expected to reside in the study location for the study period.

Exclusion Criteria:

* any known illness or disease
* pregnant
* taking antibiotics, non-steroidal anti-inflammatory drugs, dietary supplements, or vitamin and mineral supplements in the previous 12 weeks.

+Locations (1)

FacilityCityCountryStatus
Prey Kuy, Srayov and Tboung Krapeu Health CentresKampong ThomCambodia

+Publications

  • Results publication: Cirigliano E, Saint A, Pei LX, Wong CW, Wang S, Fischer JA, Kroeun H, Karakochuk CD. Iron Supplementation with Ferrous Sulfate or Ferrous Bisglycinate for 12 Weeks Does Not Influence Group B Streptococcus Colonization in Cambodian Women: A Secondary Analysis of a Randomized Controlled Trial. J Nutr. 2025 Dec;155(12):4264-4270. doi: 10.1016/j.tjnut.2025.10.014. Epub 2025 Oct 11. PMID 41082982
  • Results publication: Fischer JAJ, Pei LX, Elango R, Hou K, Goldfarb DM, Karakochuk CD. Is a Lower Dose of More Bioavailable Iron (18-mg Ferrous Bisglycinate) Noninferior to 60-mg Ferrous Sulfate in Increasing Ferritin Concentrations While Reducing Gut Inflammation and Enteropathogen Detection in Cambodian Women? A Randomized Controlled Noninferiority Trial. J Nutr. 2023 Aug;153(8):2453-2462. doi: 10.1016/j.tjnut.2023.05.029. Epub 2023 Jun 2. PMID 37271416
  • Results publication: Finlayson-Trick E, Nearing J, Fischer JA, Ma Y, Wang S, Krouen H, Goldfarb DM, Karakochuk CD. The Effect of Oral Iron Supplementation on Gut Microbial Composition: a Secondary Analysis of a Double-Blind, Randomized Controlled Trial among Cambodian Women of Reproductive Age. Microbiol Spectr. 2023 Jun 15;11(3):e0527322. doi: 10.1128/spectrum.05273-22. Epub 2023 May 18. PMID 37199608
  • Results publication: Fischer JA, Pei LX, Goldfarb DM, Albert A, Elango R, Kroeun H, Karakochuk CD. Is untargeted iron supplementation harmful when iron deficiency is not the major cause of anaemia? Study protocol for a double-blind, randomised controlled trial among non-pregnant Cambodian women. BMJ Open. 2020 Aug 16;10(8):e037232. doi: 10.1136/bmjopen-2020-037232. PMID 32801202