What Does Low Ferritin Mean? A Common Question for Vegetarians

What Ferritin Is

Ferritin is the main form in which the body stores iron, and serum ferritin levels reflect the body's iron reserves. It typically changes earlier than hemoglobin does: in the early stages of declining iron reserves, hemoglobin may still sit within the normal range even as ferritin has already begun to drop. This stage is called iron store depletion, an earlier warning sign that precedes iron-deficiency anemia.

Reference Range and Interpretation

For most adults, the reference range for serum ferritin runs roughly 15–150 ng/mL for women and 30–400 ng/mL for men, though the exact range varies somewhat by testing method and lab. A value below roughly 15 usually indicates clearly depleted iron reserves — even if hemoglobin is still normal at that point, it's worth paying attention to dietary iron intake or asking a doctor whether intervention is needed.

Practical Advice for Vegetarians

• If ferritin sits at the low end of the reference range but hemoglobin is normal, you can start with dietary adjustments (more iron-rich foods paired with vitamin C), generally followed by a retest after 2–3 months to track the trend
• If ferritin is clearly below the lower limit of the reference range, it's advisable to consult a doctor about whether iron supplementation is needed
• Inflammation can artificially raise ferritin and mask a real iron deficiency — if you have an infection or inflammation at the time of testing, let your doctor know so it can be factored in, and consider testing an inflammation marker like C-reactive protein alongside it if needed