Vitamins & Deficiencies5% of women, 2% of men in the UK

Iron Deficiency Anaemia

Also known as: Iron Deficiency, Low Iron, IDA

Iron deficiency anaemia occurs when you don't have enough iron to produce adequate healthy red blood cells. It's the most common nutritional deficiency worldwide and is very treatable.

Last reviewed: 15 January 2026

What is Iron Deficiency Anaemia?

Iron is essential for making haemoglobin, the protein in red blood cells that carries oxygen around your body. Without enough iron, you can't make enough haemoglobin, so your tissues and organs don't get as much oxygen as they need. It affects around 5% of women in the UK.

Who is affected?

Women of childbearing age (due to menstruation), pregnant women, vegetarians/vegans, and people with conditions affecting iron absorption.

Symptoms of Iron Deficiency Anaemia

Common Symptoms

  • Tiredness and lack of energy
  • Shortness of breath
  • Pale skin
  • Heart palpitations
  • Headaches
  • Dizziness or feeling faint

Less Common Symptoms

  • Brittle nails or spoon-shaped nails
  • Sore tongue (glossitis)
  • Mouth ulcers
  • Restless legs syndrome
  • Hair loss
  • Cravings for non-food items (pica)
  • Difficulty swallowing

When to Seek Urgent Help

  • Chest pain
  • Rapid heartbeat
  • Severe breathlessness

Causes & Risk Factors

Causes

  • Heavy periods (most common cause in women)
  • Pregnancy (increased iron needs)
  • Insufficient iron in diet
  • Poor iron absorption (coeliac disease, IBD)
  • Blood loss from the gut (ulcers, bowel cancer)
  • Regular use of anti-inflammatory painkillers

Risk Factors

  • Being female of reproductive age
  • Pregnancy
  • Vegetarian or vegan diet
  • Frequent blood donation
  • Heavy exercise (especially endurance sports)
  • Gastrointestinal conditions
  • History of stomach surgery

Possible Complications if Untreated

  • Heart problems if severe and prolonged
  • Pregnancy complications
  • Developmental delays in children
  • Increased infection risk

Diagnosis & Blood Tests

Iron deficiency anaemia is diagnosed through blood tests measuring your haemoglobin and iron levels.

Full Blood Count (FBC)

Measures haemoglobin and red blood cell characteristics.

What to look for: Low haemoglobin with small, pale red blood cells (microcytic, hypochromic) suggests iron deficiency.

Serum Ferritin

The best single test for iron deficiency - measures iron stores.

What to look for: Low ferritin (below 30 mcg/L) indicates depleted iron stores.

Serum Iron

Measures the amount of iron in your blood.

What to look for: Low in iron deficiency, but varies throughout the day.

Total Iron Binding Capacity (TIBC)

Measures how well your blood can transport iron.

What to look for: High TIBC suggests iron deficiency.

Transferrin Saturation

Shows what percentage of transferrin is carrying iron.

What to look for: Low transferrin saturation indicates iron deficiency.

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Treatment Options

Treatment involves iron supplements and addressing the underlying cause of the deficiency.

  • Iron tablets (ferrous sulphate, ferrous fumarate, or ferrous gluconate)
  • Vitamin C with iron to improve absorption
  • Intravenous iron if tablets not tolerated or absorbed
  • Treatment of underlying cause
  • Dietary advice to increase iron intake

Living with Iron Deficiency Anaemia

  • Take iron supplements as prescribed (usually on an empty stomach)
  • If tablets upset your stomach, take with a small amount of food
  • Drink orange juice or eat vitamin C rich foods with iron supplements
  • Avoid tea, coffee, and dairy products close to taking iron
  • Include iron-rich foods in your diet daily
  • Give it time - it takes 2-3 months to restore iron stores

Frequently Asked Questions

How long will I need to take iron supplements?

Usually for at least 3-6 months after your haemoglobin normalises to replenish your iron stores. Your doctor will guide you based on blood tests.

Why do iron tablets cause constipation?

Iron supplements can cause constipation and stomach upset. Try taking them every other day (which can be equally effective), with food, or ask about different formulations.

Are there foods that block iron absorption?

Yes, tea, coffee, calcium (dairy products), and wholegrain cereals can reduce iron absorption. Try not to have these at the same time as iron-rich meals or supplements.

Can I be anaemic without being iron deficient?

Yes, anaemia has many causes including vitamin B12 deficiency, folate deficiency, and chronic diseases. That's why proper testing is important.

When to See Your GP

  • Persistent tiredness not explained by your lifestyle
  • Shortness of breath with normal activities
  • Pale skin or inside of eyelids
  • Heavy periods
  • Blood in your stool or black, tarry stools
  • Unexplained weight loss
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