If you have fibroids and have been feeling exhausted for months — more tired than your sleep can explain, struggling to get through afternoons, finding exercise harder than it used to be — iron deficiency may be the reason. And it is one of the most overlooked consequences of heavy fibroid-related bleeding.
How Heavy Periods Deplete Iron
Each millilitre of menstrual blood contains approximately 0.5mg of iron. A normal period loses around 30–40ml total. A heavy fibroid period can lose 80ml, 120ml, or more. Over multiple cycles, this creates a cumulative deficit that the body struggles to replace from diet alone — particularly on a typical Western diet that is often relatively low in highly bioavailable iron.
The depletion happens in stages. First, ferritin (the body’s iron storage protein) falls. You can have near-zero ferritin and a normal haemoglobin — technically not anaemic, but functionally iron-depleted in ways that significantly affect how you feel. Only once ferritin is exhausted does haemoglobin begin to fall, at which point you are formally anaemic.
This staging matters because many women with heavy fibroid periods are in the ferritin-depleted stage — symptomatic and functioning poorly — but are told their blood tests are “normal” because only haemoglobin was checked. Always ask for ferritin specifically.
Symptoms of Iron Deficiency (Before Anaemia)
Persistent fatigue that sleep does not fix. Difficulty concentrating or thinking clearly (“brain fog”). Reduced exercise tolerance — getting out of breath at exertions that previously felt easy. Feeling cold when others are comfortable. Brittle or spoon-shaped nails. Hair loss or increased shedding. Restless leg syndrome, particularly at night. These symptoms are specific enough to iron deficiency that their presence alongside heavy periods should prompt a ferritin test.
What To Do
Get tested: Ask your GP for a full blood count plus ferritin. Do not accept “your blood tests are fine” without knowing whether ferritin was specifically checked. Optimal ferritin for symptom resolution is generally considered to be above 50 ng/mL, though some labs cite a normal range that starts much lower.
Food sources: Red meat has the most bioavailable haem iron, but for women managing fibroids, non-haem sources are preferable: red lentils, kidney beans, tofu, fortified cereals, pumpkin seeds, dried apricots, spinach. Always pair with Vitamin C to maximise absorption. Avoid tea and coffee within an hour of iron-rich meals.
Supplementation: If ferritin is low, dietary sources alone are often insufficient to correct the deficit while heavy bleeding continues. Ferrous fumarate or ferrous sulphate (210mg daily) is standard. Take with food to reduce stomach irritation and with orange juice for absorption. Side effects (constipation, dark stools) are common — constipation can be managed by reducing the dose initially or switching to ferrous bisglycinate (gentler on the gut).
Correcting iron deficiency alongside the dietary and lifestyle interventions described in our fibroid diet guide creates a compound effect on energy and function that neither does alone.
