Iron deficiency is considered the most significant nutritional deficiency worldwide, affecting billions of people. Iron deficiency leads to a higher prevalence of iron deficiency anaemia; a condition responsible for over 50,000 deaths annually. Since anaemia is considered a global health problem, various countermeasures have been implemented to battle this disease. One of these countermeasures is the supplementation of iron. Different iron compounds are employed for supplementation, including ferrous sulphate and ferrous fumarate. However, since only 15% of the supplemented iron is absorbed by the human body, the remaining 85% can cause various health-related issues. Due to heightened amounts of iron present in the duodenum, a disbalance in the human gut is induced, leading to e.g. excessive growth of Escherichia coli (E.coli). This study investigates the influence of 3 and 30 µM iron supplementation of ferric chloride and ferric sulphate; radiolabelled with Fe-55. These results have been reported in the form of growth curves, and the remaining amount of Fe-55 in the growth medium has been used to estimate iron uptakeby E.coli. No significant differences were observed between 3 and 30 µM iron supplementation of both compounds, indicating that iron concentration may not be considered as the main limiting growth factor of E.coli. Therefore, further research is recommended where the medium is analysed for the presence of other nutrients. Additionally, adjustments in the growth environment are recommended, to determine which growth conditions influence E.coli the most.