The present invention relates to a method for determining or approximating a patient's daily loss of iron (fe_loss), the method comprising the steps determining the patient's iron uptake (fe_uptake)； determining the quantity of iron stored within the patient's body； and determining the patient's daily loss of iron based on the patient's iron uptake (fe_uptake) and the quantity of non-functional iron stored within the patient's body. The method relates further to apparatuses and an erythropoesis stimulating medicament for use in the treatment of anaemia. Finally the present invention relates to digital storage means, a computer program product, and a computer program.
