Iron deficiencies – why can results be normal even though the body is sending warning signals?

Chronic fatigue, poorer concentration, hair loss or breathlessness during everyday activities often prompt people to have basic blood tests. It happens, however, that the full blood count stays within the normal range, and yet the body still sends signals suggesting an iron deficiency. This situation is not rare, and it results from the fact that an iron deficiency develops in stages. Understanding the mechanisms behind this process makes it possible to interpret test results more accurately and to react faster to worrying symptoms.

Why is iron so important for the body?

Iron is an element classed among the micronutrients essential for the body to function properly. Although it is most often associated with the production of red blood cells, the role of iron is much broader than it might seem.

This element takes part in transporting oxygen to all the tissues of the body, supports the normal work of the immune system, is involved in the energy processes taking place in cells and influences the functioning of the nervous system. Iron is also a component of many enzymes responsible for metabolic conversions and the production of energy.

The symptoms of iron deficiency (resulting from, among other things, malabsorption from the digestive tract or an insufficient amount of the element in the diet) may lead to a gradual decline in physical and mental capacity, even before full-blown anaemia develops.

A low level of iron in the body most often affects:

• menstruating women (this concerns heavy periods in particular);

• pregnant women;

• children and adolescents during periods of intensive growth;

• people following elimination diets;

• endurance athletes;

• people with diseases of the digestive tract (e.g. ulcerative colitis) that disturb the absorption of nutrients.

The population groups listed above show an increased requirement of the body for iron [1,2].

According to data from the World Health Organisation (WHO), iron deficiency remains one of the most common nutritional deficiencies in the world.

Why can the full blood count be normal despite an iron deficiency?

Many people equate iron deficiency solely with anaemia. Yet anaemia is most often a late stage in the development of the problem. The body has certain stores of iron, kept mainly in the form of ferritin. When the supply of iron becomes insufficient or its loss increases, the body starts to draw on these reserves. At this stage the haemoglobin concentration and the number of red blood cells may still remain within the normal range.

This means that a classic full blood count does not always make it possible to detect an early deficiency of this micronutrient. The symptoms of a lack of iron may appear earlier than abnormalities in the basic blood parameters.

Three stages in the development of iron deficiency

Stage 1 – depletion of stores

At the beginning, the concentration of ferritin, which reflects the iron stores, falls. The full blood count remains normal (with no change in the number of red blood cells).

Stage 2 – functional deficiency

The amount of iron available to the tissues decreases. The first symptoms may appear, such as fatigue, weakness or poorer concentration.

Stage 3 – iron deficiency anaemia

The haemoglobin concentration falls and characteristic changes appear in the full blood count [4-6].

Which symptoms may suggest an iron deficiency despite normal results?

The early symptoms of iron deficiency can be non-specific and easy to put down to stress, exhaustion or not getting enough sleep.

The most commonly observed symptoms include:

• chronic fatigue;

• palpitations;

• reduced tolerance of exercise;

• neurological symptoms, including disturbances of concentration;

• headaches;

• dizziness;

• a feeling of cold;

• hair loss;

• brittle nails;

• damage to the mucous membranes of the mouth;

• pale skin [1,4].

Some people also notice a worsening of mood, irritability or an increased susceptibility to infections.

Ferritin – the parameter that is often missing from basic testing

Measuring iron in the blood serum alone does not give a full picture of iron status. This parameter is subject to considerable daily fluctuations and depends, among other things, on the meals recently eaten.

Measuring ferritin, which reflects the accumulated stores of iron, has far greater diagnostic value. The WHO indicates ferritin as the basic marker for assessing the body’s iron resources.

Where do iron deficiencies come from?

An iron deficiency does not always result from an incorrect diet. In many cases the cause is an increased requirement of the body or chronic blood loss.

The most common causes include:

• too small a supply of iron – this concerns above all very restrictive or poorly balanced diets;

• an increased requirement – iron is lacking above all in pregnant women, in women during lactation, and also in people going through puberty;

• malabsorption – this may accompany coeliac disease, inflammatory bowel disease, long-term use of medicines that reduce the secretion of stomach acid, or states following operations on the digestive tract;

• chronic blood loss – most often linked with heavy periods or bleeding from the digestive tract [6,8].

What does the absorption of iron depend on?

The absorption of iron depends not only on how much of it there is in the diet, but also on the form in which it occurs and on the presence of other food components. Best absorbed is haem iron, found in products of animal origin, while non-haem iron present in vegetables, pulses and green leafy vegetables as well as cereal products is used by the body to a lesser degree.

An important role is played by vitamin C, which increases the bioavailability of non-haem iron by converting it into a form more easily absorbed in the digestive tract. In turn, some food components, such as phytates present in wholegrain cereals, polyphenols contained in coffee and tea, or large amounts of calcium consumed together with a meal, may limit the absorption of this element. For this reason, what matters is not only how much iron we supply to the body, but also the way we put together our everyday meals.

Treatment of iron deficiency

The basis of management always remains establishing the cause of the deficiency and eliminating it. At the same time it is worth ensuring an adequate supply of iron with the diet.

As mentioned earlier, the best absorbed is haem iron present in products of animal origin, such as meat, offal or fish. Non-haem iron occurring in plant products may also be a valuable element of the diet, especially when it is consumed together with vitamin C [11-12].

In situations of increased requirement or a confirmed deficiency, a doctor may recommend supplementation or pharmacological treatment.

An example of a product supporting the maintenance of normal iron status is BestFerrin, whose composition is based on freeze-dried plant ingredients and fruit extracts.

People interested in a broader range of products containing minerals can also take a look at the category: Mineral supplements BEST LAB.

More information about products supporting the everyday diet can be found at: Food supplements BEST LAB.

It should be remembered that a food supplement does not replace a varied diet or medical diagnosis, and should not be treated as a way of treating the cause of a deficiency.

FAQ – frequently asked questions

In short, an iron deficiency does not always mean anaemia visible in the full blood count. Many people experience symptoms much earlier, which is why comprehensive testing that also includes an assessment of iron stores is so important.

How can you tell that iron is lacking in the body?

The most common signs are chronic fatigue, weakness, poorer concentration, breathlessness on exertion, pale skin, hair loss and brittle nails. These symptoms are not, however, characteristic of iron deficiency alone, so they need to be confirmed by testing.

Does iron raise blood sugar?

There is no scientific evidence indicating that correctly used iron supplementation in people with a deficiency causes a rise in blood glucose levels. The interpretation of results should take into account the patient’s overall state of health.

Can an iron deficiency cause bruising?

Bruises are not a typical symptom of a low iron concentration. If they appear often or without a clear cause, it is worth consulting a doctor and having tests that include, among other things, an assessment of platelets and clotting parameters.

How can iron deficiencies be replenished as quickly as possible?

The most effective approach depends on the cause of the deficiency. It usually includes an appropriately balanced diet and (if a doctor considers it justified) supplementation or pharmacological treatment.

References