Iron deficiency is the most common nutritional deficiency in the world. It disproportionately affects women — particularly women of reproductive age with heavy periods — and within that group, African and Black women are at particularly high risk due to the combined effects of heavy menstrual bleeding, dietary patterns, and access to diagnosis and treatment.
What concerns me most in clinical practice is not the deficiency itself — that is treatable. It is how long it goes unrecognised. I regularly see women who have been running on empty for two, three, five years. Who have accepted their fatigue as their normal. Who have been told their blood tests are "fine" when what has been tested is haemoglobin — which can remain in the normal range long after iron stores are depleted.
Why African women are particularly at risk
Heavy menstrual bleeding: The most common cause of iron deficiency in pre-menopausal women. As we discussed in our fibroids and endometriosis guides, these conditions — which are more prevalent and more severe in Black women — cause significant blood loss every cycle. Blood contains iron. Losing 80ml+ per period (the threshold for "heavy") can deplete iron stores faster than diet can replenish them.
Dietary factors: Traditional African diets can be lower in haem iron (from red meat, which is absorbed most efficiently) and the phytate content of staple foods like beans, lentils, and grains can inhibit iron absorption from plant sources. This does not make African diets unhealthy — it means supplementation may be needed during high-demand periods (pregnancy, heavy periods).
Tea and coffee: Both significantly inhibit iron absorption when consumed with meals or within an hour of eating. The tannins in tea (very commonly consumed across African communities) bind to iron and prevent its absorption. This is modifiable.
Vitamin C: Enhances iron absorption significantly. Consuming iron-rich foods or supplements with a vitamin C source (orange juice, tomatoes, bell peppers) meaningfully increases absorption.
Pregnancy and breastfeeding: Iron requirements double during pregnancy. Iron deficiency in pregnancy increases risk of preterm birth, low birth weight, and postnatal depression.
Case study: Blessing running on empty for three years
Blessing, 34, a healthcare assistant from Nigeria based in Sheffield, came to see me for a routine health check. When I asked about her energy levels, she described chronic fatigue that she had "just accepted." She was sleeping 8–9 hours and waking unrefreshed. She had significant hair shedding — she was losing clumps in the shower. She was cold all the time. She had brain fog that was affecting her ability to concentrate.
Her previous blood test, done a year earlier, had shown haemoglobin of 11.8 g/dL — flagged as mildly low but not significantly so. Her ferritin had not been checked.
I checked her ferritin. It was 6 μg/L — severely depleted (normal is above 30; optimal is above 70 for symptomatic improvement).
She had classic iron deficiency, already progressing toward anaemia. She had been symptomatic for at least three years.
I prescribed high-dose oral iron (ferrous fumarate 210mg twice daily) and advised her on dietary modifications. I also referred her for investigation of the cause — an ultrasound revealed uterine fibroids.
Six weeks later: "I feel like a completely different person. The fatigue I thought was just part of my life — it's gone."
Symptoms of iron deficiency
The obvious: Fatigue and low energy — often profound and not relieved by rest. Breathlessness on exertion. Pallor (though this can be difficult to assess in darker skin — look at the inner eyelid, which should be deep pink rather than pale).
The less obvious: Hair loss — diffuse shedding, not patchy. Cold hands and feet — iron is involved in temperature regulation. Brittle nails, sometimes with a characteristic spoon shape (koilonychia) in severe deficiency. Restless legs — an uncomfortable urge to move the legs at night, significantly worse with iron deficiency. Pica — craving non-food substances (ice, chalk, soil — called geophagia, which is culturally documented across African communities). Brain fog, difficulty concentrating. Headaches. Palpitations.
The underappreciated: Reduced immunity — iron is essential for immune cell function. Mood changes — iron deficiency contributes to anxiety and depression through effects on neurotransmitter production.
The ferritin problem — the test your GP might be missing
This is clinically important: haemoglobin can remain in the normal range while iron stores are severely depleted. Many GPs check haemoglobin (as part of a full blood count) and miss iron deficiency because the haemoglobin is technically within range.
Ferritin is the storage form of iron. Low ferritin with normal haemoglobin = iron deficiency without anaemia. This stage is symptomatic and treatable, but frequently missed.
Ask your GP specifically for a ferritin test, not just a blood count. Normal lab reference ranges for ferritin are often set very low (above 10–15 μg/L) — many labs will report a ferritin of 12 as normal. Symptoms typically improve with supplementation when ferritin is brought above 70–100 μg/L.
| Ferritin level | Status |
|---|---|
| Below 15 μg/L | Iron deficiency |
| 15–30 μg/L | Borderline — symptomatic in many women |
| 30–70 μg/L | Low-normal — may still be symptomatic |
| Above 70 μg/L | Optimal for symptom relief |
| Above 300 μg/L | Potentially elevated — seek advice |
Treatment — iron supplementation that works
First-line NHS treatment: Ferrous sulphate 200mg or ferrous fumarate 210mg, taken once or twice daily. Effective but commonly causes constipation, nausea, and dark stools.
Improving tolerability: Taking iron on alternate days (rather than daily) has been shown to increase absorption and reduce side effects — the hepcidin response that limits iron absorption is lower on alternate days. Taking with food reduces side effects but also reduces absorption — a compromise often worth making for tolerability.
Vitamin C: Taking 250mg vitamin C with iron increases absorption by up to 30%.
Avoid with: Tea, coffee, calcium supplements, antacids — all inhibit iron absorption. Take iron at least 1–2 hours away from these.
Alternatives for poor tolerance: Ferrous gluconate (lower elemental iron, gentler on gut), ferric maltol (Feraccru — better tolerated, more expensive), liquid iron (easier to adjust dose).
IV iron: For people who cannot tolerate oral iron, have severe deficiency, or whose absorption is impaired (inflammatory bowel disease, bariatric surgery), IV iron infusion provides rapid, complete iron repletion in a single session. Available on the NHS in appropriate circumstances.
Recheck ferritin after 3 months of treatment to confirm response. Continue supplementation until ferritin is above 70 μg/L, then reduce to a maintenance dose — particularly if heavy periods are ongoing.
Sources: WHO — Iron Deficiency Anaemia: Assessment, Prevention and Control 2001; Camaschella C, NEJM 2015; Moretti D et al, Blood 2015 (alternate-day dosing evidence); NHS England — Iron Deficiency Anaemia clinical guideline; British Society of Gastroenterology — UK guidelines on iron deficiency anaemia 2021.