What is iron deficiency?

Iron is an important mineral that the human body requires, particularly for processes involving oxygen. The principal biological use of iron in humans is as a constituent of haemoglobin – the protein found in red blood cells that binds to oxygen. Haemoglobin enables the red blood cells to transport oxygen around the body and deliver it to the cells that need it. In short, iron is essential when it comes to keeping us alive.

Iron deficiency is when the body does not have enough iron, either because the need for iron has increased, or because the intake or absorption of iron has fallen. This shortage of iron means that the body can’t make as many red blood cells (anaemia), and, as a result, less oxygen can be carried by the blood. The ultimate consequence is that the rest of the cells in the body are running on a reduced amount of oxygen.

Iron deficiency anaemia is one of the most common forms of anaemia, and iron deficiency is also one of the most common nutritional deficiencies.

What are the symptoms of iron deficiency?

Most of the symptoms of iron deficiency are related to the associated anaemia. The shortage of iron means a shortage of oxygen reaching respiring cells, and this means the body can’t function at full capacity. Typical symptoms include:

• fatigue
• light-headedness/dizziness/headaches
• weakness
• pallor
• irritability
• shortness of breath
• heart palpitations
• brittle nails
• hair loss
• cold extremities

Iron deficiency can also affect memory and mental function, particularly in teens, while appetite may be affected in some patients (usually young children with iron deficiency anaemia).

Another strange symptom that has been reported in a number of cases is ‘pica’. This refers to unexplained cravings for strange foods or non-food items.

What causes iron deficiency?

There are several causes of iron deficiency. Most involve blood loss of some description. It is possible to develop iron deficiency simply through a lack of iron in the diet, but this is very unlikely unless the patient is pregnant. However, this will increase the risk of iron deficiency when coupled with one of the following other causes:

• Malabsorption – if your body struggles to absorb iron from food (for example caused by coeliac disease), this will lead to iron deficiency.
• Monthly periods – the most common cause of iron deficiency in women of reproductive age. Usually, only heavy periods will lead to iron deficiency/anaemia.
• Pregnancy – extra iron is needed to supply the growing baby with blood and oxygen, meaning that pregnant women often have to up their iron intake.
• Bleeding in the G-I tract – the most common cause of iron deficiency in men and post-menopausal women is stomach ulcers. 
• Stomach cancer 
• Taking NSAIDs (Non-steroidal anti-inflammatory drugs) can cause bleeding in the stomach.
• Bowel cancer
• Angiodysplasia
• Chronic kidney disease
• Inflammatory bowel disease
• Crohn’s disease
• Ulcerative colitis

Any other condition or incident that causes blood loss could lead to iron deficiency, even if only temporarily, for example, after giving blood, or losing blood due to trauma.

How is iron deficiency normally treated?

Treatment usually involves taking iron supplements and/or eating more iron-rich foods, such as red meat, fish, dark green leafy vegetables, beans, pulses, brown rice and eggs. However, in some cases, this will not be enough, and the underlying cause will have to also be addressed. It is important for the doctor to monitor the patient, taking more blood tests after a few weeks to see if haemoglobin levels are returning to normal levels.

What happens if iron deficiency is left untreated?

If iron deficiency is left untreated for long enough, patients are at a higher risk of developing: 

• frequent illness and infection
• heart complications such as an abnormally fast heartbeat
• lung complications

If patients are deficient in iron and are pregnant, there is a high risk of complications before and after birth. 

What are the associated risk factors?

There are some risk factors associated with iron deficiency. These include: 

• being vegetarian
• being female
• being 65 or older
• donating blood on a frequent basis

Can I make any lifestyle changes that might help?

There are many adjustments one can make when it comes to improving their overall iron intake. Patients who are iron-deficient will normally be recommended to eat plenty of the following:

• red meat
• seafood
• beans
• leafy greens such as spinach
• cereal
• pasta
• bread
• food or drink that contains Vitamin C

What iron-focused diet is recommended for vegetarians?

If a patient is iron-deficient and a vegetarian, they are encouraged to include the following in their diet on a regular basis: 

• potatoes
• spinach
• beans
• nuts
• seeds
• legumes
• soybeans
• tofu
• lentils
• tomatoes
• mushrooms
• olives
• oats
• quinoa
• dark chocolate