Why iron is so important for our body
Iron is an essential trace element involved in numerous metabolic processes. It is particularly well known for its role in forming haemoglobin, the red blood pigment that transports oxygen from the lungs to the tissues. The supply of oxygen to the muscles (via myoglobin), energy production in the mitochondria and the function of the immune system also depend on an adequate iron supply.
If iron is lacking over a longer period, this can noticeably impair physical and mental performance. Iron deficiency is one of the most common micronutrient deficiencies worldwide and, in Austria, primarily affects women of childbearing age, pregnant women, adolescents during growth and ambitious athletes.
Iron deficiency: recognising the symptoms
Iron deficiency usually develops gradually. The body initially draws on its iron stores before measurable changes appear in the blood count. Even in this early phase, the first symptoms may become noticeable.
Typical symptoms of iron deficiency
- Persistent tiredness, exhaustion and lack of drive
- Problems with concentration and memory
- Headaches, dizziness
- Pallor of the skin and mucous membranes
- Brittle nails, hair loss, cracked corners of the mouth
- Sensitivity to cold
- Palpitations or shortness of breath on exertion
- Reduced athletic performance
- Restless legs (restless legs symptoms)
Since these symptoms are non-specific and may have other causes, a medical assessment is advisable. Self-diagnosis or taking iron supplements on one's own initiative is not recommended, as excess iron can also pose long-term health risks.
Iron deficiency and sport: why active people are particularly at risk
The topic of "iron deficiency in sport" frequently comes up in training and health forums – and for good reason. Physically active people, particularly in endurance sports, have an increased iron requirement. Several factors are responsible for this:
- Increased iron loss via sweat, urine and the gastrointestinal tract
- Mechanical haemolysis (destruction of red blood cells), for example during running
- Increased need due to greater muscle mass and an increased number of mitochondria
- Possible inflammation-related changes in iron metabolism after intensive exertion
Iron deficiency in sport often becomes noticeable through an unexplained performance plateau, longer recovery times, premature fatigue or an elevated resting heart rate. The subjective feeling of "heavy legs" can also be a sign. Before adjusting your training plan, it is therefore worth taking a look at the relevant laboratory values.
Diagnostics: which laboratory values are meaningful?
A sound diagnosis is not based on a single value, but on a combination of several parameters. This makes it possible to distinguish whether there is a pure storage iron deficiency, a functional iron deficiency or already manifest iron deficiency anaemia.
Important parameters at a glance
- Ferritin value: Reflects the body's iron stores and is regarded as the central marker. Low ferritin values indicate empty stores. However, ferritin can be elevated in cases of inflammation, infections or liver disease and may mask a deficiency.
- Transferrin saturation: Indicates how much of the transport protein transferrin is actually loaded with iron. A low value suggests inadequate iron availability.
- Haemoglobin (Hb): Only decreases in advanced deficiency and indicates manifest anaemia.
- Red cell indices (MCV, MCH): Help to further classify the type of anaemia.
- CRP: Often measured alongside in order to rule out inflammation as a cause of elevated ferritin values.
- Soluble transferrin receptor (sTfR): Can be helpful as a supplementary measure for identifying functional iron deficiency.
Which ferritin values are considered optimal is debated among experts and depends on age, sex and the individual situation. Very physically active people or those with persistent symptoms often benefit from a differentiated assessment within a clinical context, rather than relying on reference ranges alone.
Possible causes of iron deficiency
A deficiency can have various causes. A medical assessment serves not only to confirm the diagnosis but also to identify the underlying cause.
- Increased need: Growth, pregnancy, breastfeeding, intensive physical activity
- Reduced intake: A one-sided diet, vegetarian or vegan diet without adequate planning
- Impaired absorption: Coeliac disease, chronic inflammatory bowel disease, condition following stomach or bowel surgery, Helicobacter pylori infection
- Chronic blood loss: Heavy menstruation, gastrointestinal bleeding, frequent blood donations
- Chronic diseases: Renal insufficiency, chronic inflammation
In men and postmenopausal women in particular, iron deficiency should not be attributed too readily to diet. Here it is especially important to have possible blood losses or absorption disorders investigated medically.
Medical assessment and possible therapeutic approaches
As part of a medical assessment, the patient's history, physical examination and laboratory findings are brought together. Depending on the result, further investigations may be useful, for example a gastroenterological assessment if a source of bleeding is suspected.
Possible therapeutic approaches
- Nutritional advice: Iron-rich foods such as pulses, whole grain products, green vegetables, nuts and – in a mixed diet – meat and fish can support iron supply. Vitamin C improves the absorption of plant-based iron, while coffee, tea and dairy products can inhibit it when consumed close to a meal.
- Oral iron preparations: Are prescribed by a doctor when a deficiency has been confirmed. Dosage, intake interval and duration should be determined individually, and treatment success should be monitored through laboratory tests.
- Intravenous iron administration: May be considered if oral preparations are not sufficiently effective, are not tolerated or if certain conditions are present. This therapy is carried out exclusively under medical supervision.
Treatment without prior diagnostics is not recommended. Both the choice of preparation and the duration of therapy should be based on individual findings.
Conclusion
Iron deficiency can manifest itself in many ways – from general exhaustion and concentration problems to declining athletic capacity. Differentiated laboratory diagnostics including ferritin value, transferrin saturation, blood count and inflammation parameters form the basis for a well-founded assessment. Anyone who notices typical symptoms should have their iron status checked by a doctor instead of taking supplements on their own. This allows the cause and treatment to be tailored individually and safely.
This article does not replace medical advice.