Check age and sex before comparing intervals
Both Quest and Labcorp separate ferritin intervals by age and sex. Labcorp updated its assay page in October 2026 and uses several adult female age bands. An undated graphic containing one universal ferritin interval can therefore misrepresent the laboratory report it is meant to explain. [1] [2]
Distinguish a reference interval from a decision threshold
WHO guidance discusses ferritin in the assessment of iron status and the influence of inflammation. Reference populations, deficiency thresholds and treatment goals are different concepts. A result needs to be interpreted in the context for which a threshold was developed. [3]
Read iron studies together
Ferritin is also an acute-phase reactant. A clinician may consider evidence of inflammation and other iron-related measurements rather than interpreting ferritin alone. A value inside a printed interval does not answer every question about iron status, and a higher result is not automatically a better one. [3]
Keep the clinical question explicit
Store the reason for testing, the exact assay interval and relevant related results with the value. Our source review did not identify a universal Pfeiffer, Walsh or Hoffer ferritin optimum. Use source-specific interpretation rather than treating a marketing target as an established treatment goal. [1] [2] [3]
| Marker | Quest example | Labcorp example |
|---|---|---|
| Ferritin | Men 19–59: 38–380; women 19–40: 16–154 ng/mL. Assay source ↗ | Men ≥20: 30–400; women 20–40: 30–150 ng/mL. Assay source ↗ |
These notes explain sources and testing context. They do not diagnose a condition, select a personal supplement dose or replace professional medical advice.