Iron Deficiency

Learn about the causes & risk factors of iron deficiency, the 3 stages and symptoms of iron deficiency, and find answers to frequently asked questions about iron deficiency.

What is Iron Deficiency?

Iron is an essential mineral responsible for various vital physiological functions. Iron deficiency is a condition characterised by insufficient levels of iron in the body. 

This essential mineral is needed in adequate levels for production of haemoglobin, a component of red blood cells that carries oxygen to tissues throughout the body. 

When iron levels are insufficient, the body struggles to produce enough healthy red blood cells.

Read our dedicated article for more information about healthy iron levels for women.

What are Iron Deficiency Symptoms?

Symptoms of iron deficiency include fatigue, weakness, pale skin, shortness of breath, headaches, dizziness, cold hands and feet, brittle nails, and an increased susceptibility to infections. Speak to your doctor or health professional if you think you may be experiencing symptoms of iron deficiency. 

What are the Causes of Iron Deficiency?

Iron deficiency can result from various factors, with inadequate dietary intake being a primary cause.

Diets lacking sufficient iron-rich foods, especially in people following vegetarian or vegan diets, can contribute to iron deficiency. Chronic blood loss caused by menstrual bleeding, gastrointestinal issues or other medical conditions, can deplete iron stores over time. Pregnancy, rapid growth in children, and intense physical activity can increase iron requirements, making certain populations more susceptible. Additionally, some people may have difficulty absorbing iron from food sources, increasing their risk of deficiency.

For information on the symptoms of iron deficiency, see our page for Iron Supplements for Iron Deficiency.

Risk Factors of Low Iron

The following groups of people have a higher risk of insufficient iron intake:


Due to the loss of blood during their menstrual cycle, women are at a higher risk of having low iron levels that potentially leads to a deficiency in iron.

Vegetarians & Vegans

People who don’t eat meat usually may have a greater risk of low iron if they don’t eat enough haem iron rich foods. Haem iron is found in meat, fish, and poultry.

Children & Infants

Children may require iron as they are growing rapidly. Infants who do not get enough iron from breast milk or formula are also at risk. Speak to your doctor if you are concerned about this.

Frequent Blood Donors

People who regularly give blood as blood donations can reduce their iron stores. Ensure you are consulting your health professional before you give blood.

What are the 3 stages of Iron Deficiency?

Iron deficiency progresses through three stages, each reflected increasing degrees of severity.

Iron Depletion

The first stage of iron deficiency is iron depletion, where the body's iron stores begin to decline, but haemoglobin levels and red blood cell levels remain normal. You may feel low energy, or other mild symptoms at this stage.

Iron-Deficient Erythropoiesis

As iron continues to be insufficient, the condition advances to the second stage, and affects the production of red blood cells. The body struggles to produce an adequate number of red blood cells, and symptoms may become apparent.

Iron Deficiency Anemia

The final and most severe stage is iron deficiency anaemia, characterised by low haemoglobin levels, diminished red blood cell production, and symptoms advance to those such as fatigue, weakness, and pale skin.

Frequently Asked Questions

  • Does iron deficiency affect the immune system?

    Iron plays an essential role in immune system function1. Iron is necessary for immune cells proliferation and maturation, associated with the production of a particular response to infection. Iron helps contribute to the antibody response, meaning healthy levels are important for a healthy immune system.

  • Can iron deficiency cause hair loss?

    Yes, iron deficiency can contribute to hair loss, as iron is required for the proper growth and maintenance of hair follicles. Insufficient iron levels can disrupt the hair growth cycle, leading to increased shedding and a higher likelihood of hair loss. Importantly, changes in hair growth should not be immediately attributed to iron deficiency. If you are experiencing any hair concerns, please speak to your doctor or health professional.

  • Can iron deficiency cause weight gain?

    Iron deficiency is not typically associated with weight gain; in fact, it is more commonly linked to weight loss as it can lead to a decrease in energy levels and overall metabolic rate. If you are experiencing any concerns about changes in weight, please speak to your doctor or health professional.

  • How to help fix iron deficiency?

    Addressing iron deficiency involves incorporating iron-rich foods into the diet, such as lean meats, poultry, fish, beans, lentils, and fortified cereals. Additionally, pairing these foods with sources of vitamin C enhances iron absorption. Iron deficiency medication may be recommended in some cases of iron deficiency – remember to always read the label and follow the directions for use. For personalised guidance, anyone experiencing symptoms of iron deficiency should consult with their doctor or health professional to develop an appropriate and sustainable plan for improving iron levels.

  • How much iron do I need a day?

    The average person needs to absorb just a small amount of iron each day to stay healthy. However, to achieve this, we need to consume several times that amount. This is because our bodies absorb only a fraction of the iron contained in the foods we eat2. Additionally, iron needs may vary between groups. Women and children may require higher levels of iron to stay healthy, for example.

  • Can men be iron deficient?

    Yes, men can experience iron deficiency. While iron deficiency anaemia is more prevalent in women, particularly due to menstrual blood loss, men can still develop iron deficiency, often as a result of insufficient dietary intake, chronic medical conditions, or gastrointestinal issues.

Related Articles

Why is Iron Important?

Learn why iron is important for health and how to recognise the symptoms of iron deficiency. Finetune your iron intake through diet and supplementation.

Iron Levels for Women

Understand the importance of iron for women's health. Discover what normal and low iron levels are and how to maintain optimal iron balance.


1. Ward RJ, Crichton RR, Taylor DL, et al. Iron and the immune system. J Neural Transm. 2011;118:315-328.

2. NHMRC, Australian Government Department of Health and Ageing, New Zealand Ministry of Health. Nutrient Reference Values for Australia and New Zealand. Iron [cited 5 February 2024]. Canberra: NHMRC; 2006.