Table 1: Diagnostic criteria defining iron depletion, IDE, and IDA based on traditional indicators of iron status and CRP.

Traditional indicators of iron status and CRP
Hb (g/L)CRP (mg/L)SF (µg/L)TIBC (µmol/L)and/orTS

SF cutoff < 15 µg/L regardless of CRP level
 Iron depletion<15
 IDE <15>72or<16

SF cutoffs < 15 or <50 µg/L w/o or w/ inflammation, respectively
 Iron depletion w/o inflammation≤5<15
 Iron depletion w/ inflammation>5<50
 IDE w/o inflammation≤5<15>72or<16
 IDE w/ inflammation>5<50>72or<16
 IDA w/o inflammation<110≤5<15>72or<16
 IDA w/ inflammation<110>5<50>72or<16

IDE: iron deficient erythropoiesis; IDA: iron deficiency anemia; CRP: C-reactive protein; Hb: hemoglobin; SF: serum ferritin; TIBC: total iron binding capacity; TS: transferrin saturation; w/o: without; w/: with.
Reference sources for the cutoffs were as follows: Hb [19]; CRP [7, 3133]; SF [6, 30]; TIBC [22, 23]; TS [14, 19, 23].
The choice “and/or” applies to the last two biochemical parameters.
SF cutoffs were adjusted for inflammation using the C-reactive protein (CRP): w/o inflammation: CRP < 5 mg/L; w/ inflammation: CRP ≥ 5 mg/L.
Without or with concomitant IDE and IDA.