Ferritin

Pick Ordered or Not ordered to see the note.

Indicated when

• —Fatigue, restless legs symptoms, hair loss, pica, or reduced exercise tolerance, where iron deficiency without anemia is a real and treatable cause even with a normal hemoglobin [7]
• —Heavy menstrual bleeding, pregnancy, a vegetarian or vegan diet, bariatric surgery or malabsorption, frequent blood donation, or endurance athletes, all recognized risk factors for iron deficiency [5]
• —Confirmed anemia, to help distinguish iron deficiency anemia from other causes [5]
• —Monitoring known iron deficiency during repletion, or monitoring ferritin trends during treatment of confirmed iron overload [European Association for the Study of the Liver 2022]

Not indicated when

• —Routine annual or 'wellness panel' screening in an asymptomatic adult with no iron-deficiency risk factors; population-based general screening is not recommended [5, 8]

Why not

Ferritin is an acute-phase reactant, so it can rise into the 'normal' or even high range during infection, inflammation, or liver disease, masking a true iron deficiency; results should be interpreted alongside a marker of inflammation and the clinical picture rather than in isolation [6].

Better first step

For fatigue with no other suggestive features, ferritin (with hemoglobin/CBC) is itself an appropriate, low-cost first step, since it is the single test of choice for diagnosing iron deficiency; add a marker of inflammation such as CRP if inflammation or chronic disease is suspected, since that changes how the ferritin result should be read [5, 6]. If iron deficiency is confirmed and unexplained in an at-risk adult, with no clear dietary or menstrual cause, investigate for an underlying source, including gastrointestinal blood loss [9].

Typical ND rationale

An ND may order ferritin in a patient with fatigue, hair loss, restless legs, or heavy periods, reasoning that iron deficiency can exist and cause real symptoms well before hemoglobin drops low enough to be labelled anemia, and that a standard complete blood count alone can miss it.

Ontario coverage & CONO orderability

OHIP status

insured

Listed by name in the 2026 Schedule of Benefits for Laboratory Services (L329 Ferritin, fee $2.97). Insured when ordered by a physician, midwife, or NP who has clinically assessed the patient; the same test ordered by a naturopathic doctor is not an insured service and is billed privately (Reg. 552 s.22(1); SOB-LS 2026 preamble). Note: the Schedule specifies that L329 (Ferritin) and L139 (iron, TIBC, and per cent saturation) cannot both be claimed for the same patient; see the Iron studies (serum iron, TIBC, transferrin saturation, transferrin) record.

CONO orderable

Yes — CONO list #63

CONO list item 63, blood: 'Ferritin.'

Linked conditions

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

Counselling script

“Ferritin is the best first test for low iron, and low iron without anemia is a real, common cause of tiredness, restless legs, or hair loss that a standard blood count alone can miss, so given what you're describing, it's reasonable to check today. Without a symptom or risk factor like that pointing to iron deficiency, ferritin isn't a useful test to repeat every year just as routine screening, and I'd rather order it when there's a clear reason.”

Revisit if

• —New or worsening fatigue, restless legs, hair loss, or pica
• —Heavy menstrual bleeding
• —New pregnancy
• —Starting a vegetarian or vegan diet, or bariatric surgery
• —Known or suspected inflammation or chronic disease affecting interpretation

References

1. [1]Ontario Ministry of Health (2026). Ontario Health Insurance Plan: Schedule of Benefits for Laboratory Services (effective April 1, 2026) - L329 Ferritin. linkFerritin (L329) is listed by name in the 2026 OHIP Schedule of Benefits for Laboratory Services
2. [2]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
3. [3]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
4. [4]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
5. [5]BC Ministry of Health (BC Guidelines and Protocols Advisory Committee) (2019). Iron Deficiency - Diagnosis and Management. linkFerritin is the test of choice for diagnosing iron deficiency; iron deficiency causes symptoms even without anemia; population-based general screening is not recommended
6. [6]World Health Organization (2020). WHO guideline on use of ferritin concentrations to assess iron status in individuals and populations. linkFerritin is an acute-phase reactant and should be interpreted alongside markers of inflammation
7. [7]Royal College of Physicians (Clinical Medicine) (2021). Iron deficiency without anaemia: a diagnosis that matters. linkIron deficiency without anemia is at least twice as common as iron deficiency anemia and is poorly recognised by clinicians
8. [8]College of Family Physicians of Canada / Choosing Wisely Canada (2026). Family Medicine: Fifteen Tests and Treatments to Question. linkDon't do annual screening blood tests unless directly indicated by the patient's risk profile
9. [9]British Society of Gastroenterology (2021). British Society of Gastroenterology guidelines for the management of iron deficiency anaemia in adults. linkUnexplained iron deficiency anemia in at-risk adults is an indication for investigating an underlying cause, including gastrointestinal blood loss