Ferritin
What This Test Measures
Iron storage protein
Conventional vs. Functional Optimal Range
The gap between these ranges is why you feel terrible with "normal" labs. Conventional medicine waits for disease. Functional medicine optimizes for health.
Gabriel's Take
A ferritin of 15 can sit inside some labs' ranges, yet a ferritin below 30 is a sensitive sign of iron deficiency (American Family Physician), and low stores can come with fatigue, hair shedding, restless legs and brain fog. Gabriel's optimal band is 50-100 for men and women. For restless legs, hair shedding, low thyroid (Hashimoto's) or athletes, Gabriel's goal band is 75-150. Ferritin also rises with inflammation, infection, fatty liver and alcohol, so read it with CRP and transferrin saturation. Persistently above 300, or transferrin saturation above 45%, calls for a hemochromatosis check. Full guide: askgabriel.com/guides/ferritin-levels.
When This Test Is High
Hemochromatosis, chronic inflammation, liver disease
When This Test Is Low
Iron deficiency, anemia, heavy periods
Related Conditions
Iron deficiency: fatigue, hair loss, restless legs; High: hemochromatosis, inflammation
Recommended Follow-Up
If low, find the cause (heavy periods, gut blood loss, poor absorption) and check iron, TIBC, transferrin saturation and CRP before taking iron with a clinician's guidance; if high, check CRP and liver enzymes, and test for hemochromatosis if it stays above 300 or transferrin saturation is above 45%