Iron deficiency is the single most overlooked consequence of fibroid-related heavy bleeding — and it is significantly more common than clinical anaemia in women with fibroids. Understanding the difference matters enormously for how you feel day to day.
Haemoglobin vs Ferritin: Why Both Matter
Haemoglobin measures the oxygen-carrying protein in red blood cells. Ferritin measures stored iron. The body depletes ferritin first — iron stores drain before haemoglobin falls. This means you can have near-zero iron stores (ferritin) with technically normal haemoglobin. The lab result says “normal” but you feel exhausted, cold, and unable to concentrate.
This is one of the most common clinical oversights for women with heavy periods. Always ask for ferritin tested specifically alongside haemoglobin. Optimal ferritin for symptom resolution is generally considered above 50 ng/mL — many labs cite lower thresholds as “normal” that still leave women functionally iron-depleted.
Symptoms of Iron Depletion Before Anaemia
Persistent fatigue that sleep does not fix. Brain fog and difficulty concentrating. Getting breathless at exertions that used to be easy. Feeling cold when others are comfortable. Hair loss or increased shedding. Brittle nails. Restless legs at night. These symptoms appearing together alongside heavy periods should prompt a ferritin test — not reassurance that “your bloods are fine.”
How Much Iron Does Heavy Bleeding Actually Remove?
Each millilitre of menstrual blood contains approximately 0.5mg of iron. A normal period loses 30–40ml. A heavy fibroid period can lose 80–150ml or more over its course. At 100ml blood loss, that is 50mg of iron per cycle — far exceeding what most women replace through diet alone. Over three or four cycles, the cumulative deficit becomes significant even if each individual period does not seem catastrophic.
Food Sources of Iron
Non-haem iron (from plant sources) is less bioavailable than haem iron but avoids the red meat association with higher fibroid risk. Best non-haem sources: red lentils, kidney beans, fortified breakfast cereals, pumpkin seeds, spinach, tofu, dark chocolate (70%+), dried apricots. Always pair with a vitamin C source — bell peppers, tomatoes, orange juice, strawberries — which increases non-haem iron absorption by 3–4 times. Avoid tea and coffee within an hour of iron-rich meals (tannins block absorption). For the broader dietary picture, see our complete fibroid diet guide.
When To Supplement
If ferritin is below 30 ng/mL, dietary sources alone are insufficient to correct the deficit while heavy bleeding continues. Ferrous fumarate 210mg daily is standard. Take with food and orange juice. Ferrous bisglycinate is gentler on the gut if ferrous fumarate causes constipation. Retest ferritin at 3 months to confirm the dose is working.
The Energy Impact Is Significant
Women who correct iron deficiency often describe the improvement in energy and cognitive function as dramatic — faster and more noticeable than any other single intervention. This is not a supplement that takes months to feel. Correcting ferritin from 10 to 60 ng/mL over 2–3 months produces a meaningful shift in how functional you feel daily. If heavy periods are part of your picture, see our article on heavy bleeding from fibroids for the full management picture alongside iron repletion.
