Alternate Day vs. Daily Iron Supplementation in Iron Depleted Women

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

• 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.