Iron Deficiency - Iron Study Thresholds

For the diagnosis of absolute iron deficiency (ID), various cutoffs of ferritin and TSAT have been defined in normal states, inflammatory conditions, advanced age, heart failure, CKD, and ESRD.

Setting	Defined Cutoffs
Most circumstances	Ferritin <15 ng/mL (more specific) Ferritin <30 ng/mL (more sensitive)
Inflammatory conditions or advanced age	TSAT <16% and ferritin < 100 ng/mL TSAT < 20% with inflammation and ferritin < 100 ng/mL
Heart failure	Ferritin < 100 Ferritin < 300 and TSAT < 20%
Preoperative	Ferritin < 100 and/or TSAT < 20%
CKD	Ferritin < 500 and TSAT < 30%
Dialysis	Ferritin < 200 or TSAT < 20%

References

Ning S, Zeller MP. Management of iron deficiency. Hematology [Internet]. 2019 Dec 6 [cited 2021 Jul 2];2019(1):315–22. Available from: https://doi.org/10.1182/hematology.2019000034