The common lower standard values for ferritin are set too low. A ferritin concentration < 30 ng/mL in both women and men is considered evidence of insufficient iron storage. The first symptoms of iron deficiency often occur at ferritin levels below 50 ng/mL. An increase of the lower standard values for ferritin to at least 50 ng/mL is proposed by several authors. Reference values are basically dependent on the measurement method and on the composition of the selected reference collective. The detection of iron deficiency requires the combined use of several laboratory measurement parameters for the correct assessment of the iron metabolism.