What Is Iron Deficiency?


Iron deficiency is a prevalent nutritional health issue that affects millions of people worldwide.1 This condition arises when the body lacks an adequate amount of iron, which is an essential mineral required for various vital functions. Iron plays a crucial role in the body's ability to transport oxygen and support cellular metabolism. Without sufficient iron, the body's overall health and well-being can be compromised.1

Iron deficiency is especially concerning because of its widespread impact on individuals of all ages and backgrounds. Anyone can experience the effects of insufficient iron levels. In this article, we will delve into the causes, symptoms, risks, and solutions of iron deficiency. By understanding this condition better, we can proactively prevent and address it.

Causes of iron deficiency

There are several underlying factors that contribute to iron deficiency. Understanding these causes is crucial in addressing the condition effectively.2 The primary causes include:

  • Inadequate dietary intake: Iron-rich foods are essential for maintaining optimal iron levels, and a diet lacking in these foods can lead to iron deficiency. Common iron-rich foods include red meat, poultry, fish, beans, lentils, spinach, and fortified cereals.
  • Poor iron absorption: Even with a diet rich in iron, certain factors can hinder the body's ability to absorb it efficiently. Substances like tannins in tea and phytates in whole grains can inhibit iron absorption. Consuming calcium-rich foods alongside iron-rich foods can also interfere with absorption.

Certain life stages and conditions require increased iron intake, for instance:

  • Growth and development: Children and adolescents undergoing growth spurts need more iron to support their expanding blood volume and muscle mass.
  • Pregnancy and lactation: Pregnant people require extra iron to support the growth of the foetus and the increased blood volume. The lactating parent will also need higher iron levels for milk production.

Recognising these causes helps us adopt strategies to prevent iron deficiency and ensure that we meet the body's iron requirements effectively.

Signs and symptoms

Iron deficiency can manifest through a range of signs and symptoms, which may vary in severity.3 Recognizing these indicators is vital for early detection and prompt intervention. Some common signs and symptoms of iron deficiency include:

  • Fatigue and weakness: One of the earliest and most common symptoms of iron deficiency is persistent fatigue and weakness.4 This occurs because iron is a key component of haemoglobin, which is the molecule responsible for transporting oxygen in the blood. Insufficient iron can lead to decreased oxygen delivery to cells, resulting in tiredness and weakness.
  • Pale skin and nail beds: Haemoglobin also gives blood its red colour, contributing to the rosy hue of the skin and nail beds. Iron deficiency can cause paleness in these areas due to reduced haemoglobin production.5
  • Shortness of breath: Inadequate oxygen transport can lead to shortness of breath, especially during physical activities. This is because the body's demand for oxygen increases during exercises, and a lack of iron can limit the amount of oxygen available to muscles and tissues.
  • Headaches and dizziness: Insufficient oxygen supply to the brain can result in headaches and dizziness. These symptoms can negatively impact daily activities and overall quality of life.6
  • Restless legs syndrome: Iron deficiency has also been linked to restless legs syndrome (RLS), a condition characterised by uncomfortable sensations in the legs and an irresistible urge to move them. RLS can disrupt sleep and lead to further complications.

These signs and symptoms should not be ignored, especially when they persist over time. Consulting a healthcare professional for proper evaluation and diagnosis is essential if any of these indicators are experienced. Early intervention can prevent the progression of iron deficiency and its potential complications.


Diagnosing iron deficiency involves a combination of medical assessments and laboratory tests. Proper diagnosis is essential to accurate identification of the condition and its underlying causes.7 Healthcare professionals use various methods to determine whether an individual has iron deficiency. 

Blood tests

  • Haemoglobin levels: Haemoglobin is a protein found in red blood cells that carries oxygen throughout the body. Low haemoglobin levels can indicate anaemia, which is often caused by iron deficiency.
  • Serum ferritin levels: Ferritin is a protein that stores iron. Measuring serum ferritin levels can provide insights into the body's iron stores. Low levels indicate iron deficiency.

Additional tests to identify underlying causes

  • Complete blood count (CBC): This test measures different components of the blood, including red blood cells, white blood cells, and platelets. Abnormalities in these components can indicate iron deficiency or other related conditions.
  • Iron studies: These tests measure various aspects of iron metabolism, such as transferrin (a protein that transports iron), total iron-binding capacity (TIBC), and transferrin saturation. These values help assess how effective the body is at using iron.

Accurate diagnosis ensures appropriate treatment and helps rule out other potential health issues. If iron deficiency is confirmed, healthcare providers can then recommend the most suitable interventions to address the condition effectively.

Groups at risk

Certain groups of individuals are more susceptible to iron deficiency due to their specific physiological needs or dietary habits. Recognizing these high-risk groups is important for targeted preventive measures and early intervention.8 The groups at higher risk of iron deficiency include:

  • Children and adolescents: Rapid growth and development during childhood and adolescence increase the body's demand for iron. As children grow, their blood volume and muscle mass expand, necessitating sufficient iron intake to support these changes.
  • Pregnant people: Pregnancy places significant demands on an individual’s iron stores. Iron is essential for both the pregnant person's increased blood volume and the development of the foetus. Without adequate iron intake, pregnant people are at a higher risk of developing iron deficiency anaemia.
  • Vegetarians and vegans: Plant-based diets can be lower in heme iron (only found in animal products), which is more readily absorbed by the body. Non-heme iron from plant sources is not as easily absorbed; therefore, vegetarians and vegans may require dietary adjustments or supplementation to meet iron needs.
  • People with certain medical conditions: Certain medical conditions can interfere with iron absorption or increase iron loss. Conditions such as celiac disease, inflammatory bowel disease, and gastrointestinal surgeries can impact the body's ability to absorb iron effectively.

Identifying these high-risk groups helps healthcare professionals tailor their recommendations and interventions. Individuals within these groups should be particularly vigilant about monitoring their iron intake and addressing any signs of deficiency promptly.

Health implications of iron deficiency

Iron deficiency can have far-reaching health implications beyond the immediate symptoms. It can impact various bodily functions and overall well-being.9 Understanding these potential consequences emphasises the importance of addressing an iron deficiency in a timely manner:

  • Anaemia: One of the most significant consequences of iron deficiency is anaemia. Anaemia occurs when the body lacks enough red blood cells or haemoglobin to carry sufficient oxygen to tissues and organs. This can lead to fatigue, weakness, and reduced physical and cognitive performance.
  • Impaired cognitive function: Inadequate oxygen supply to the brain due to iron deficiency can impair cognitive functions such as concentration, memory, and problem-solving. This is particularly concerning for children and adolescents, as iron is crucial for optimal brain development.
  • Weakened immune system: Iron is essential for immune function. A deficiency can weaken the immune system, making individuals more susceptible to infections and illnesses. This is a particular concern in vulnerable populations, such as young children and the elderly.
  • Impact on physical performance: Iron deficiency can negatively affect physical performance, including endurance and exercise capacity. Athletes and active individuals may experience reduced stamina and increased fatigue.

By understanding the potential health consequences of iron deficiency, individuals can be motivated to prioritise their iron intake and take proactive steps to prevent or address the condition. Early intervention and appropriate management can mitigate these effects and promote better overall health.

Prevention and management

Preventing and managing iron deficiency involves adopting a balanced approach to diet, considering supplementation if necessary, and being mindful of factors that enhance or hinder iron absorption.10 Here are key strategies for prevention and management:

  • Balanced diet: Incorporating a variety of iron-rich foods into your diet can help prevent iron deficiency. These include lean meats, poultry, fish, legumes (beans and lentils), fortified cereals, nuts, seeds, and leafy greens. Consuming a diverse range of these foods helps ensure adequate iron intake.
  • Iron supplementation: In cases where dietary sources are insufficient or when a healthcare professional recommends supplementation, iron supplements can be beneficial. It is important to follow your healthcare provider's guidance to avoid taking excessive amounts of iron, which can lead to complications.
  • Vitamin C: Consuming vitamin C-rich foods (e.g., citrus fruits, strawberries, bell peppers) alongside iron-rich foods can enhance iron absorption. Vitamin C helps convert non-heme iron (from plant sources) into a more absorbable form.
  • Cooking techniques: Certain cooking methods can increase iron absorption. For example, soaking beans and lentils before cooking, using cast-iron cookware, and avoiding excessive tea or coffee consumption with meals can aid in better iron absorption.

By implementing these strategies, individuals can significantly reduce their risk of iron deficiency and its associated health implications. Regular monitoring of iron levels and consultation with a healthcare professional can ensure that preventive measures are effective and personalised to each individual's needs.

When to seek medical help

Knowing when to seek medical assistance for iron deficiency is crucial to preventing complications and receiving appropriate treatment. If you experience any of the following scenarios, consider consulting a healthcare professional:

  • Persistent symptoms: If you notice ongoing signs of iron deficiency, such as fatigue, weakness, or pale skin, despite efforts to improve your iron intake through diet or supplements
  • High-risk groups: If you belong to a high-risk group, such as pregnant people, children, vegetarians/vegans, or individuals with specific medical conditions, regular monitoring of iron levels and seeking professional guidance is essential
  • Unexplained symptoms: If you experience symptoms like fatigue, shortness of breath, or headaches without a clear cause, a healthcare provider can help identify if iron deficiency is contributing to these issues
  • Underlying conditions: If you have an existing medical condition that could affect iron absorption or utilisation, such as celiac disease or gastrointestinal disorders, a healthcare professional can help manage your iron needs
  • Guidance on supplementation: If you are considering iron supplementation, it is best to consult a healthcare provider to determine the appropriate dosage and duration based on your individual requirements

Receiving timely medical help ensures accurate diagnosis, proper treatment, and tailored advice to address iron deficiency effectively and maintain optimal health.


Iron deficiency poses a significant health concern with wide-ranging effects on energy levels, cognitive function, immunity, and more. By recognizing the causes, symptoms, and risks associated with iron deficiency and by implementing strategies like a balanced diet, supplementation when advised, and improved iron absorption techniques, we can actively prevent and manage this condition. Prioritising iron intake and seeking medical support when necessary empower us to maintain vitality and overall well-being.


  1. Pettit K, Rowley J, Brown N. Iron deficiency. Paediatrics and Child Health [Internet]. 2011 Aug 1 [cited 2023 Aug 31];21(8):339–43. Available from: https://www.sciencedirect.com/science/article/pii/S1751722211000679
  2. Camaschella C. Iron-deficiency anemia. Longo DL, editor. N Engl J Med [Internet]. 2015 May 7 [cited 2023 Aug 31];372(19):1832–43. Available from: http://www.nejm.org/doi/10.1056/NEJMra1401038
  3. Cappellini MD, Comin‐Colet J, De Francisco A, Dignass A, Doehner W, Lam CS, et al. Iron deficiency across chronic inflammatory conditions: International expert opinion on definition, diagnosis, and management. American J Hematol [Internet]. 2017 Oct [cited 2023 Aug 31];92(10):1068–78. Available from: https://onlinelibrary.wiley.com/doi/10.1002/ajh.24820
  4. Patterson AJ, Brown WJ, Powers JR, Roberts DCK. Iron deficiency, general health and fatigue: Results from the Australian Longitudinal Study on Women’s Health. Qual Life Res [Internet]. 2000 May 1 [cited 2023 Aug 31];9(5):491–7. Available from: https://doi.org/10.1023/A:1008978114650
  5. Mahadea D, Adamczewska E, Ratajczak AE, Rychter AM, Zawada A, Eder P, et al. Iron deficiency anemia in inflammatory bowel diseases—a narrative review. Nutrients [Internet]. 2021 Nov [cited 2023 Aug 31];13(11):4008. Available from: https://www.mdpi.com/2072-6643/13/11/4008 
  6. Pamuk GE, Top MŞ, Uyanık MŞ, Köker H, Akker M, Ak R, et al. Is iron-deficiency anemia associated with migraine? Is there a role for anxiety and depression? Wien Klin Wochenschr [Internet]. 2016 Dec 1 [cited 2023 Aug 31];128(8):576–80. Available from: https://doi.org/10.1007/s00508-015-0740-8
  7. Polin V, Coriat R, Perkins G, Dhooge M, Abitbol V, Leblanc S, et al. Iron deficiency: From diagnosis to treatment. Digestive and Liver Disease [Internet]. 2013 Oct 1 [cited 2023 Aug 31];45(10):803–9. Available from: https://www.sciencedirect.com/science/article/pii/S1590865813000947
  8. Grosbois B, Decaux O, Cador B, Cazalets C, Jego P. [Human iron deficiency]. Bull Acad Natl Med. 2005 Nov 1;189(8):1649–63; discussion 1663-4. 
  9. Swanson CA. Iron intake and regulation: implications for iron deficiency and iron overload. Alcohol [Internet]. 2003 Jun 1 [cited 2023 Aug 31];30(2):99–102. Available from: https://www.sciencedirect.com/science/article/pii/S0741832903001034
  10. Burke RM, Leon JS, Suchdev PS. Identification, prevention and treatment of iron deficiency during the first 1000 days. Nutrients [Internet]. 2014 Oct [cited 2023 Aug 31];6(10):4093–114. Available from: https://www.mdpi.com/2072-6643/6/10/4093
This content is purely informational and isn’t medical guidance. It shouldn’t replace professional medical counsel. Always consult your physician regarding treatment risks and benefits. See our editorial standards for more details.

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Dr. Lewis Spencer

Doctor of Philosophy - PhD, Biomedical Sciences, General, University of Derby

Lewis is a PhD graduate, where his research focus was on obesity and diabetes treatment with GLP-1 Receptor Agonists. He also has 6 years' experience as an Associate Lecturer in Sport and Exercise Physiology and Research Methods. He is now working as a Health Information Specialist.

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