15 healthy young women with non-anemic iron deficiency will participate in the study. On 4 different days the investigators will take two blood samples (one in the morning at 8 am, before the iron intake and one in the afternoon at 4 pm) to determine the plasma hepcidin level. The intake of the iron supplements will be at least 48 hours apart from each other, to exclude any impacts of the previous iron intake to the next measurement.~The participants will take the iron supplement supervised at 8 am after overnight fasting.~All blood samples will be performed for analysis of CRP and hepcidin. The investigators will measure the CRP in the blood sample to exclude any impacts of inflammation to the hepcidin measurement and use a CRP ≤5mg/l as a cut-off. If the CRP is higher than 5mg/l the investigators will exclude the measurement from our analyses and repeat the measurement at another day.~The first two blood samples will be taken at 8 am and at 4 pm on the same day and after overnight fasting to find the baseline hepcidin, the other blood samples will be taken at 8 am before the iron intake and at 4 pm also on the same day and also after overnight fasting.
The study participants will take 3 different doses of iron supplements at 8 am, on 3 different days. By taking blood samples in the morning and afternoon, the investigators will determine the effects of the iron supplements on plasma hepcidin and compare them to baseline plasma hepcidin values.