Iron studies (serum iron, TIBC, transferrin saturation, transferrin)

Pick Ordered or Not ordered to see the note.

Indicated when

• —Elevated or borderline-high ferritin, to assess for iron overload or hemochromatosis: HFE-related hemochromatosis is suggested when both ferritin (above the upper limit of normal) and transferrin saturation (above 45%) are elevated [7, 9]
• —A ferritin result that is hard to interpret because of known or suspected concurrent inflammation, where transferrin saturation can help clarify true iron status [World Health Organization 2020]
• —Suspected iron overload from another cause, such as repeated transfusions or excessive iron supplementation

Not indicated when

• —First-line investigation of suspected iron deficiency: serum iron, TIBC, and transferrin saturation are not routinely useful for this and add little over ferritin alone [6, 8]
• —Ordering HFE genetic testing before both ferritin and transferrin saturation are known to be elevated [7]

Why not

Serum iron is highly variable through the day and with recent diet or supplements, and ordering the full iron panel routinely when ferritin alone would answer the clinical question adds cost and complexity without changing management [6]. Ferritin, and by extension a panel built around interpreting it, can also be elevated by nonalcoholic fatty liver disease or alcoholic liver disease independent of true iron overload, which is a recognized source of false-positive concern for hemochromatosis [10].

Better first step

For suspected iron deficiency, order ferritin (with hemoglobin) first; reserve the iron/TIBC/transferrin-saturation panel for clarifying an abnormal ferritin, screening for hemochromatosis, or when iron overload is genuinely being considered [8, 6].

Typical ND rationale

An ND may order a full iron panel alongside or instead of ferritin, reasoning that transferrin saturation gives a fuller picture of iron status in one draw and can catch iron overload as well as deficiency.

Ontario coverage & CONO orderability

OHIP status

insured

Iron, total, with iron binding capacity and per cent saturation (L139, fee $1.28) and transferrin (L554, fee $5.22) are both listed by name in the 2026 Schedule of Benefits for Laboratory Services, insured when ordered by a physician, midwife, or NP who has clinically assessed the patient; ND-ordered testing is not insured and is billed privately (Reg. 552 s.22(1); SOB-LS 2026 preamble). The Schedule specifies that L139 is 'not to be claimed with L329' (Ferritin) for the same patient, an administrative billing rule: a physician ordering both ferritin and the iron panel together should expect only one to be paid, though this does not affect whether the panel is clinically or privately available.

CONO orderable

Yes — CONO list #82, #123

CONO list item 82, blood: 'Iron, total – with iron binding capacity and per cent saturation'; item 123, blood: 'Transferrin.'

Linked conditions

• Iron deficiency without anemia ↗
• Hereditary hemochromatosis (iron overload) ↗
• tired ↗

Counselling script

“For checking low iron, ferritin alone usually answers the question, so I don't routinely add the full iron panel on top of it. This panel becomes useful when we're specifically screening for iron overload, or hemochromatosis, or when a ferritin result is hard to interpret because of inflammation. I don't see a reason for that today, but I'll order it if your ferritin comes back high or if there's a family history of iron overload.”

Revisit if

• —Ferritin returns elevated or borderline-high
• —Family history of hereditary hemochromatosis
• —Unexplained liver disease, joint pain, diabetes, or skin bronzing
• —Ferritin result difficult to interpret because of known inflammation

References

1. [1]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026) - L139 Iron, total with iron binding capacity and per cent saturation. linkIron, total with iron binding capacity and per cent saturation (L139) is listed by name in the 2026 OHIP Schedule
2. [2]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026) - L554 Miscellaneous proteins - Transferrin. linkTransferrin (L554) is listed by name in the 2026 OHIP Schedule
3. [3]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkCommunity lab tests are insured only when ordered under the Schedule by an authorized prescriber
4. [4]Government of Ontario (e-Laws) (2026). Health Insurance Act, R.R.O. 1990, Reg. 552: General, s. 22 (insured laboratory services). linkA lab test is insured only when ordered by a physician, midwife, or NP who has clinically assessed the patient
5. [5]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026). linkTests ordered by anyone other than an authorized provider, including NDs, are not insured services
6. [6]Canadian Society of Clinical Chemists / Choosing Wisely Canada (2025). Clinical Biochemistry recommendations. linkDo not routinely order an iron profile (iron, UIBC/TIBC, transferrin saturation) in the investigation of iron deficiency
7. [7]Canadian Society of Clinical Chemists / Choosing Wisely Canada (2025). Clinical Biochemistry recommendations. linkDon't order HFE-related hemochromatosis molecular testing unless both ferritin (above upper limit of normal) and transferrin saturation (above 45%) are elevated
8. [8]BC Ministry of Health (BC Guidelines and Protocols Advisory Committee) (2019). Iron Deficiency - Diagnosis and Management. linkSerum iron, iron binding capacity, and transferrin saturation are not routinely useful for investigating iron deficiency anemia
9. [9]European Association for the Study of the Liver (2022). EASL Clinical Practice Guidelines on haemochromatosis. linkDiagnostic thresholds for provisional iron overload based on transferrin saturation and ferritin in HFE homozygotes
10. [10]American College of Gastroenterology (2019). ACG Clinical Guideline: Hereditary Hemochromatosis. linkSerum ferritin may be elevated by nonalcoholic fatty liver disease or alcoholic liver disease independent of true iron overload