How Can I Tell If My Body Is Iron Deficient?

About This Article: Zoom Health has supplied home health tests to UK customers for nearly 20 years. This guide draws on our experience helping thousands of people understand and monitor iron deficiency anaemia. We’ve combined current NHS and NICE guidance with practical insights from our customers. Always consult a healthcare professional for diagnosis and medical advice.

What Is Iron Deficiency Anaemia?

Around 2 billion people worldwide are affected by iron deficiency anaemia, making it a significant global health challenge.

Iron is a mineral your body uses to make haemoglobin, a protein in red blood cells. Haemoglobin carries oxygen throughout your body. Without adequate oxygen transport, your body cannot function efficiently, leading to iron deficiency anaemia—a condition where your red blood cells don’t carry enough oxygen.

According to NHS guidance on iron deficiency anaemia, this is one of the most common types of anaemia and affects people across all ages and backgrounds.

Symptoms to Look Out For

You may be suffering from iron deficiency or iron deficiency anaemia if you experience any of the following:

• Lack of energy and persistent fatigue
• Dizziness and headaches
• Shortness of breath during normal activity
• Pale skin or pale colouring inside your eyelids
• Heart palpitations or irregular heartbeats
• Tongue and mouth soreness or a swollen tongue
• Brittle nails that may become spoon-shaped (koilonychia)
• Restless leg syndrome (uncomfortable sensations in your legs)

Some people also experience unusual cravings for ice, starch, or dirt—a condition called pica, which can indicate severe deficiency.

If you notice any combination of these symptoms lasting more than a few weeks, it’s worth getting checked. Don’t assume tiredness is just stress or age—persistent fatigue is your body’s signal that something needs attention.

What Causes Iron Deficiency Anaemia?

Iron deficiency anaemia develops when your body loses iron faster than it can replace it, or when you’re not consuming enough iron-rich foods.

Common causes include:

• Heavy or prolonged menstruation (lasting over seven days)
• Pregnancy and breastfeeding (increased iron demands)
• Inflammatory bowel diseases such as Crohn’s disease or ulcerative colitis
• Internal bleeding from stomach ulcers, haemorrhoids, or other GI issues
• Non-steroidal anti-inflammatory drugs (NSAIDs) like ibuprofen (regular use can damage the stomach lining)
• Coeliac disease (affects nutrient absorption)
• Blood loss from surgery or injury

The NHS provides comprehensive guidance on iron deficiency causes, and your GP can help identify which factors apply to your situation.

At-Risk Groups

Certain groups are more vulnerable to iron deficiency and should monitor their levels more closely:

Pregnant women and new mothers: Pregnancy increases iron demand by up to 50%. A full blood count during pregnancy screening is routine, and your midwife will advise if supplementation is needed.

Women with heavy periods: If your periods last longer than seven days or are unusually heavy, discuss this with your GP. Iron loss during menstruation is one of the leading causes of deficiency in women.

Vegans and vegetarians: Plant-based diets can be rich in iron, but the type matters. Plant iron (non-haem iron) is absorbed less efficiently than iron from meat (haem iron). Regular B12 and iron checks are worthwhile.

Athletes and active people: Intensive exercise increases iron demands and can cause minor GI bleeding.

Children: Growing bodies have higher iron needs. If your child is unusually tired, pale, or struggling at school, iron deficiency could be a factor.

People with digestive disorders: Coeliac disease, Crohn’s disease, and other GI conditions reduce nutrient absorption.

How Much Iron Do You Need?

The recommended daily allowance (RDA) for iron varies by age and gender:

• Adult men (19–64 years): 8.7 mg per day
• Adult women (19–50 years): 14.8 mg per day (higher due to menstrual losses)
• Women over 51: 8.7 mg per day
• Pregnant women: 27 mg per day
• Children (7–10 years): 8.7 mg per day
• Teenagers (11–18 years): 11.3–14.8 mg per day (depending on sex)

Most people can meet these targets through diet alone if they eat a balanced range of iron-rich foods. If you’re at higher risk or have confirmed deficiency, your GP may recommend supplementation.

Iron-Rich Foods for Different Diets

Haem iron (meat sources—most easily absorbed):

• Red meat: beef, lamb (100g serving ~2–3 mg iron)
• Poultry: chicken, turkey (100g serving ~1 mg iron)
• Fish and shellfish: mackerel, tuna, oysters (100g serving ~1–2.5 mg iron)
• Liver and organ meats (100g ~5–7 mg iron—most concentrated source)

Non-haem iron (plant and fortified sources—less easily absorbed, but sufficient):

• Dark leafy greens: spinach, kale (cooked 100g ~3–4 mg iron)
• Legumes: lentils, chickpeas, beans (cooked 100g ~1.5–3 mg iron)
• Fortified cereals and grains (check labels: 4–18 mg per serving)
• Pumpkin and sunflower seeds (30g ~3–4 mg iron)
• Tofu and tempeh (100g ~1.5–3.5 mg iron)
• Dried apricots and figs (50g ~2–3 mg iron)

Factors That Affect Iron Absorption

Not all iron is created equal. What you eat with your iron-rich foods matters significantly.

Enhancers (eat these alongside iron-rich foods):

• Vitamin C: Dramatically improves non-haem iron absorption. Pair lentils with tomatoes, spinach with orange juice, or beans with bell peppers. Aim for 25–75 mg vitamin C per meal.
• Meat, fish, poultry: Even small amounts of haem iron help your body absorb plant iron in the same meal.
• Acidic foods: Vinegar, lemon juice, and tomato sauce improve absorption.

Inhibitors (consume separately from iron-rich meals):

• Tea and coffee: Contain tannins that bind iron and reduce absorption by up to 60%. Wait 1–2 hours after an iron-rich meal.
• Calcium supplements: Can interfere with iron absorption; take separately (2+ hours apart).
• Whole grains and bran: Contain phytates that inhibit absorption. This is less of an issue if you soak or ferment grains.
• Dairy products: Calcium in milk, cheese, and yoghurt can reduce absorption—eat these separately from main iron sources.

This is why a simple lentil stew with tomatoes is more beneficial than the same lentils served with tea.

Is There an At-Home Iron Levels Test I Can Use?

Yes. Testing for iron deficiency is straightforward and convenient.

You have two options: ask your GP to arrange a blood test through the NHS, or use an at-home anaemia test kit to check your iron levels privately in the comfort of your own home.

At-home test kits are designed to be simple and painless. They measure ferritin levels—a protein that stores iron in your cells—which gives a reliable snapshot of your iron status.

How to Use an Iron Test Kit

The at-home iron testing process is easy and takes about 15 minutes.

Step 1: Prepare

Read the instruction leaflet carefully. It includes everything you need: a sterile lancet (small needle), a capillary tube for collecting blood, and an indicator card.

Step 2: Collect Your Sample

Using the sterile lancet, prick your finger to obtain a small drop of blood. This is quick and causes minimal discomfort. Place the drop on the indicator card.

Step 3: Process the Sample

Add the diluent (provided) to the blood sample, then wait 10 minutes. The reaction will produce a clear result.

Step 4: Read Your Result

After 10 minutes, you’ll see either a negative or positive result:

• Negative result: Your ferritin levels are normal and iron deficiency is unlikely.
• Positive result: Your ferritin levels are low, suggesting possible iron deficiency.

When to Seek Medical Help

Don’t ignore persistent symptoms. Contact your GP if:

• You feel unusually tired for more than two weeks despite adequate sleep
• You experience shortness of breath during normal daily activities
• You notice unusual cravings for ice, starch, or other non-food items
• Your nails become spoon-shaped or unusually brittle
• You have heavy periods lasting longer than seven days
• You’re pregnant and suspect iron deficiency
• You’re a parent and your child seems unusually fatigued or pale

Your GP can arrange comprehensive blood tests to confirm iron status and check for underlying causes such as stomach problems, internal bleeding, or digestive disorders.

Early diagnosis and treatment prevent serious complications, help you regain energy, and improve your overall quality of life. Regular check-ups are especially important if you’re at higher risk of deficiency.

A Final Note on Balance

While iron deficiency is common and manageable, it’s worth noting that too much iron can also be harmful. A condition called iron overload (haemochromatosis) is less common but can cause joint pain, fatigue, and skin discolouration if left untreated.

The goal is balance: enough iron for your body’s needs, monitored appropriately. Your GP can help you find that sweet spot.

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Zoom Health is a leading UK supplier of home health tests and earplugs. We’ve helped thousands of people monitor their health over many years.

This post was originally published in November 2020. It was last updated in November 2025.

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