Iron Absorption and Losses in Young South African Women Living Without and With Overweight and Obesity

Inclusion Criteria: * Of African descent * BMI of 18.5 to 24.9 kg/m2 for participants living without OW/OB and BMI ≥ 28 kg/m2 for participants living with OW/OB * Having low to moderate inflammation-adjusted iron stores (ferritin ≤50 µg/L) * Absence of low-grade inflammation (CRP\<2 mg/l) for participants living without OW/OB and presence of low-grade inflammation CRP 2-20 mg/l) for participants living with OW/OB * Planning to reside in the study area for at least 2 years Exclusion Criteria: * Hemoglobin \< 11 g/dl * Treated or self-reported chronic or malabsorptive disorder * Current use of chronic anti-inflammatory medication, like corticosteroids or non-steroidal anti-inflammatory medication * Pregnancy or planning to become pregnant in the next 2 years * Lactation * Fear of needles or experiencing vaso-vagal episodes when exposed to blood * Difficulty drawing blood due to poor quality veins * Blood donation in the past 4 months or plans to donate blood during the study * On a weight-loss diet or program or planning to start the same during the study * Smoking * Unwillingness to stop taking iron and /or vitamin C-containing supplements during phase 1 of the study * Regular use of antacids, proton pump inhibitors or H2 blockers Additional inclusion criteria applicable to phase 2 of the study * Labelled with stable iron isotope (tracer) for a minimum of one year * Willingness not to start or stop contraceptive use during the 6 months * BMI ≥ 18.5 to 24.9 kg/m2 for participants living without OW/OB and BMI ≥ 28 kg/m2 for participants living with OW/OB Additional exclusion criteria applicable to phase 2 of the study \- Blood transfusion, intravenous iron infusion, blood donation or significant blood loss during the equilibration period