Iron Deficiency

What is iron deficiency?

Iron is essential for producing certain proteins in the body, particularly haemoglobin — the molecule in red blood cells that carries oxygen to tissues. When iron levels are low, haemoglobin production may fall, leading to iron deficiency anaemia.. However, iron deficiency can occur without anaemia. Many people with low iron stores still experience symptoms even if their haemoglobin level is within the normal range.

What are the symptoms of iron deficiency?

Symptoms can range from mild to severe and may include:

• Tiredness or fatigue

• Shortness of breath

• Reduced exercise tolerance

• Dizziness or light-headedness

• Pale or sallow skin

• Headaches

• Difficulty concentrating

• Heart palpitations (racing or irregular heartbeat)

• Restless legs

• Brittle nails or hair thinning

• Craving to eat ice or non-food substances (e.g. clay, dirt)

What causes iron deficiency?

Iron deficiency can result from one or more of the following:

1. Blood loss

This is the most common cause of iron deficiency. Blood loss can be sudden or gradual.

• Menstrual bleeding (especially heavy periods)

• Gastrointestinal (GI) bleeding, which may be overt (visible blood) or occult (silent bleeding). Potential causes of GI iron loss include:

  • Peptic ulcers

  • Inflammatory bowel disease

  • Helicobacter pylori infection

  • Bowel cancer or large colorectal polyps

  • Gastric cancer

  • Complications of cirrhosis and portal hypertension

  • Vascular malformations of the GI tract

  • Any condition which causes overt GI bleeding

• Other causes: blood donation, trauma, or surgery

2. Increased physiological demand

• Pregnancy

• Intense physical activity, which may lead to increased iron loss through sweat or microscopic bleeding

3. Inadequate dietary intake

• Diets low in iron-rich foods, especially vegetarian or vegan diets without proper planning

4. Poor absorption of iron

• Coeliac disease

• Inflammatory bowel disease (IBD)

• Previous gastrointestinal surgery (e.g. gastric bypass)

How is iron deficiency diagnosed?

Diagnosis involves:

• Full blood count (FBC) – to assess for anaemia

• Iron studies: the main test to see if the body has enough iron is called "ferritin." The other helpful markers is called "transferrin saturation".

Additional tests may be needed to determine the underlying cause, such as:

• Gastroscopy and colonoscopy

• Coeliac serology

• Pelvic ultrasound – in premenopausal women with heavy periods

How is iron deficiency treated?

1. Treat the underlying cause

• It's important to identify and correct the reason for low iron stores (e.g. heavy menstrual bleeding, coeliac disease, blood loss from the gut). This may involve blood tests to screen for coeliac disease, endoscopic evaluation (gastroscopy and colonoscopy) +/- gynaecology assessment/review (for pre-menopausal women)

2. Iron supplementation

• Dietary intake alone is rarely sufficient to restore low iron stores.

• Oral iron supplements are typically first-line. In Australia, common brands include Ferrograd-C and Maltofer.

  • These are usually taken once daily or every second day

  • Iron tablets may cause nausea, constipation, and dark-coloured stools

  • Treatment duration is usually several months

• Intravenous (IV) iron is alternative option and will quickly restores iron levels. Multiple studies have found that an iron infusion is more effective and more tolerable than the oral (by mouth). In Australia, common forms of IV iron include Ferinject and Monofer. An iron infusion may be recommended when:

  • Oral iron is not tolerated (i.e. causes GI upset or constipation)

  • Iron stores need to be replenished quickly

  • There is significant anaemia or ongoing blood loss

  • Malabsorption is present