Iron Absorption From a Nutritional Iron Supplement

Inclusion Criteria:

• Female aged 18 to 45 years
• Plasma ferritin <30 µg/L
• Body mass index (BMI) 18.5 kg/m2 - 24.9 kg/m2.
• Body weight <65 kg.
• Signed informed consent
• Sufficient command of English (mother tongue or B2 level)

Exclusion Criteria:

• Anemia, defined as hemoglobin (Hb) <120 g/L (<12.0 g/dL).
• Elevated systemic inflammatory markers (C-reactive protein >5.0 mg/L).
• Chronic digestive, renal and/or metabolic diseases
• Chronic medications (except for contraceptives)
• Use of vitamin, mineral, or pre-/Pprobiotic supplements in the 2 weeks before or during the study
• Blood transfusion, blood donation or significant blood loss (>400ml) over the past 4 months
• Difficulty with blood withdrawal
• Pregnancy (tested in serum/urine) or intention to become pregnant during the course of the study
• Lactation
• Previous participation in a study using stable isotopes or participation in any clinical study within the last 30 days
• Participants who cannot be expected to comply with the study protocol (e.g. not available on certain study appointments)
• Inability to understand the information sheet and the informed consent form due to cognitive or language reasons
• Smoking (>1 cigarette/week)
• Vegan diet (the standardized breakfast contains plain whole milk yogurt and butter)

Special exclusion criteria for participants in the MRI imaging sub-study (n=9):

• Presence of a heart pacemaker, neurostimulator, or any other active implanted electronic device.
• Use of a hearing aid that cannot be safely removed for the MRI examination.
• Use of removable dentures that cannot be safely removed for the MRI examination.
• History of surgery on the head or heart involving implanted material that is not confirmed MRI-safe.
• Presence of metallic objects in the body (e.g. implants, magnets, metal splinters, gunshot fragments, tattoos, piercings, or surgical clips) that are not confirmed MRI-safe.
• History of metal splinter injury (e.g. ocular foreign body) or occupational exposure associated with increased risk of retained metal fragments.