In this study the investigators will compare iron absorption from 3 doses of iron (5, 10, 15 mg, given as either Spatone™ or ferrous sulphate). Our primary objective is to determine iron absorption from each preparation by measuring stable isotope (57Fe) incorporation into haemoglobin.

The study is designed to comprehensively evaluate iron absorption by directly comparing the efficacy of Spatone™ with that of ferrous sulphate. It aims to gather dose-response information to understand how varying doses influence iron absorption. Additionally, the study seeks to investigate the impact of iron absorption on serum hepcidin levels, which is a significant factor as elevated hepcidin levels can inhibit both the absorption and utilization of iron. Understanding these dynamics is vital for improving treatments for conditions related to iron deficiency and for optimizing iron supplementation strategies. Three doses of iron either as Spatone™ or ferrous sulphate will be given to each participant. Our hypotheses are: 1. There will be a dose-dependent decrease in fractional iron absorption from both Spatone™ and ferrous sulphate preparations; 2. There will be no significant difference in iron absorption between Spatone™ and ferrous sulphate; 3. Spatone™ and ferrous sulphate will not affect hepcidin levels, even at the highest dose of each preparation used in this study.

Inclusion Criteria:

• Healthy pre-menopausal women
• Aged 19-49 years
• With low iron stores (below 30 μg/L serum ferritin; normal range 30-100 μg/L).

Exclusion Criteria:

• Allergy to iron supplements
• BMI above 25
• Pregnant
• Post-menopausal women
• History of alcohol or substance abuse
• Reported history of CVD, diabetes, cancer, kidney, liver or intestinal disease, gastrointestinal disorder
• Use of drugs likely to alter gastrointestinal function
• Donated blood recently (within the last 3 months prior to screening visit)

Biological females