Dietary iron needs for U.S. adults

Dietary Iron Requirements in US Adults

Not applicable Interventional Pennington Biomedical Research Center · NCT07139821

This project will test how much iron healthy men and premenopausal women ages 18–50 need by giving a safe stable iron isotope and measuring blood levels over 12 weeks.

Quick facts

PhaseNot applicable
Study typeInterventional
Enrollment300 (estimated)
Ages18 Years to 50 Years
SexAll
SponsorPennington Biomedical Research Center Academic / other
Locations2 sites (Baton Rouge, Louisiana and 1 other locations)
Trial IDNCT07139821 on ClinicalTrials.gov

What this trial studies

Current Dietary Reference Intakes for iron are based on a small number of studies in European populations, so this study will apply the stable iron isotope dilution technique in a representative sample of U.S. adults. Participants receive a safe, orally administered stable iron isotope (or have previously received one and completed equilibration) and are followed during a 12-week monitoring period. Blood samples are collected every four weeks to measure isotopic composition and infer iron absorption and losses. The resulting data will be used to inform updates to U.S. dietary iron guidelines.

Who should consider this trial

Good fit: Healthy men and premenopausal women aged 18–50 who can stop iron supplements and tobacco, avoid recent and ongoing blood donation, and agree to isotope dosing and periodic blood draws are ideal candidates.

Not a fit: Pregnant or lactating women, people outside the 18–50 age range, those with active iron-related medical conditions, or those unable to stop supplements, smoking, or blood donation are unlikely to benefit from participation.

Why it matters

Potential benefit: If successful, the results could lead to updated U.S. dietary iron guidelines that better prevent iron deficiency and iron deficiency anemia.

How similar studies have performed: Stable iron isotope dilution has been used in prior, mainly European studies to estimate iron needs, but applying it in a representative U.S. adult sample is relatively novel.

Eligibility criteria

Show full inclusion / exclusion criteria
Inclusion Criteria:

* Males and premenopausal females age 18-50 y
* Previously participated in an iron stable isotope study or willing to consume an oral stable iron isotope and undergo a one-year equilibration period
* Willing to refrain from iron-containing supplements for the duration of the study
* Willing to refrain from tobacco smoking for the duration of the study
* Have not donated blood 3 months prior to the start of the study and willing to refrain from donating blood for the duration of the study
* Willing to have blood stored for future use
* Able and willing to comply with study requirements and consent to participate

Exclusion Criteria:

* Females: pregnant or lactating or plans to become pregnant during the study period
* Inability to provide informed consent and engage in informed consent procedures
* Plans to relocate outside the study area

Where this trial is running

Baton Rouge, Louisiana and 1 other locations

Study contacts

How to participate

  1. Review the eligibility criteria above with your treating physician.
  2. Visit the official trial page on ClinicalTrials.gov for the most current contact information and recruitment status.
  3. Contact the listed study coordinator or principal investigator to request pre-screening. Pre-screening is free and never obligates you to enroll.
Conditions Iron AbsorptionIron absorptionIron lossesIron requirementsIron deficiencyIron deficiency anemiaIron isotopes
Last reviewed 2026-06-13 by the Find a Trial editorial team. Information on this page is for educational purposes and is not medical advice. Always consult qualified healthcare professionals about clinical trial participation.