The equation named after the Swiss physician calculates the amount of necessary iron to adequately substitute the iron deficit in anemia.
The WHO recommends gender-specific hemoglobin target values for women (120 g/l) and men (130 g/l). In addition, iron deficiency can be divided into the following stages: storage iron deficiency (stage I), iron-deficient erythropoiesis (stage II) with e. g. hypochromic erythrocytes with normal hemoglobin and iron-deficiency anemia (stage III). Generally, there is an indication for iron substitution from stage II, but pregnancy or comorbidities such as renal insufficiency requiring dialysis must also be considered.