Iron Deficiency

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What is Iron Deficiency?

Iron deficiency occurs when the level of this element in the body is lower than the norm. It is worth being aware that low iron levels can lead to many health problems, primarily iron deficiency anemia.

What is Iron?

IronTrusted Source is a chemical element marked with the symbol Fe. In terms of its mass, it is the chemical element most frequently found on Earth. Iron makes up most of the Earth's outer and inner core composition.

Physically, pure iron is a shiny, silvery, hard, and refractory metal. For many years, iron has been used in the form of alloys with carbon, manganese, chromium, or molybdenum. In its free state, iron occurs in meteoroids and low-oxygen environments because iron reacts with water and oxygen. It also appears in the human body in hemoglobin, tissues, muscles, bone marrow, blood proteins, enzymes, ferritin, hemosiderin, and plasma.

Normal Level

The typical iron levels in human blood vary according to age and gender. In men, normal iron levels range from 60-180 μg/ml, while women have a 60-160 μg/dl range.

Iron deficiencyTrusted Source is characterized by different stages. The pre-latent stage (ferritin level below 20 mg/l) and the latent stage (below 15 mg/l) relate to the level of iron stores in the body and typically do not affect human functioning. However, overt iron deficiency manifests in clinical symptoms, such as anemia, weakness, pale skin, headache, and rapid heartbeat, when the level of iron in the body reaches a critically low point.

Iron Deficiency: What Is, Causes, Symptoms, and Tests

Chronic fatigue, concentration problems, and unusual reflexes may occur when insufficient iron reaches the brain. Long-term deficiency is marked by brittle and weakened hair, brittle nails, and reduced cold tolerance.

Dangerously low levels of iron in the blood can also result in severe neurological effects, especially in individuals with chronic inflammatory conditions or those undergoing dialysis.


Low ferritinTrusted Source, which is an indicator of the level of iron stores in the body, can have various causesTrusted Source, the most important of which are:

Unfortunately, the lack of adequate iron levels can also be caused by chronic diseases. Cancer, kidney disease, and rheumatoid arthritis may lead to the so-called anemia of chronic disease, which is often associated with low ferritin levels. It is particularly destructive for the diseased body because iron deficiency additionally weakens the heart, which has to work harder to deliver the appropriate amount of oxygen to the body.


Many people are also concerned about the relationship between iron levels and lifestyle. Therefore, it is worth mentioning the most troubling issues:


The most common symptomsTrusted Source indicating low iron levels include:

Iron deficiency symptoms are more prevalent in adults mindful of their physical appearance. These symptoms include brittle hair and nails, dry skin, and cracked mouth corners. These symptoms serve as warning signs indicating the need to evaluate iron levels.

Interestingly, insufficient iron levels in the body may lead to previously unknown symptoms, such as a change in tongue appearance or discomfort in the legs, particularly at night.


In children and adolescentsTrusted Source, iron deficiency can significantly impact cognitive functions, including concentration and learning abilities. It is crucial to remember that these symptoms may also be related to other health issues. Therefore, consulting a physician who can diagnose the cause and recommend appropriate treatment is significant if these symptoms appear.

Neurological Symptoms

Iron deficiency manifests in a range of neurological symptomsTrusted Source, often difficult to directly attribute to the deficiency. Commonly observed neurological symptoms include chronic fatigue, headaches, dizziness, and difficulty concentrating. Iron deficiency can also result in restless legs syndrome, characterized by an unpleasant sensation prompting the need to move the legs, especially at night, resulting in sleep disturbances. In severe cases, decreased iron levels can impact the ability to maintain balance and coordination and cause tinnitus.

Neurological symptoms of iron deficiency also include changes in behavior. Iron affects the synthesis and signaling of the neurotransmitters dopamine, noradrenaline, adrenaline, and 5-hydroxytryptamine. Several iron-dependent enzymes synthesize these neurotransmitters. However, iron deficiency in the brain rarely causes reduced expression or activity of these enzymes.

Iron Deficiency: What Is, Causes, Symptoms, and Tests

Skin, Hair, and Nails

Iron deficiency can cause various skin symptoms, but they do not appear in every person with this deficiency.

One of the most characteristic symptoms of low iron levels is pale skin, which may be accompanied by dark circles under the eyes and frequent bruising on the body. Iron is an important component of hemoglobin, which transports oxygen to various body parts, including the skin, giving it a healthy color. Some patients with iron deficiency complain of itchy skin and pimples typical of acne, but studies have not proven a relationship between these symptoms and iron deficiency.

Moreover, specialists believe iron deficiency can lead to hair weakness and loss. It is caused by insufficient oxygen supply to the hair follicles.

Nails become thin and brittle and sometimes may take on a spoon-shaped shape. Iron deficiency affects their health because it limits the oxygen supply to the nail cells.

Bone, Muscle, and Joint Pain

Iron deficiency, known primarily for causing anemia, may affect muscle and bone function but is not directly recognized as a cause of specific orthopedic or rheumatological conditions. Still, iron deficiency can contribute to certain musculoskeletal symptoms.

Iron deficiency can lead to general weakness and fatigue, which can sometimes be felt as back pain or even bone pain. However, it is worth being aware that there is no direct evidence that iron deficiency causes bone or joint pain. Although iron is significant for overall health, osteoarthritis pain usually has other causes.

Iron deficiency can cause pain during exercise because muscles not receiving enough oxygen tire more quickly. There is a feeling of heaviness in the legs, fatigue, and general discomfort, which may be felt as leg pain.

If you experience back, muscle, bone, joint, or leg pain, it is crucial to consult a doctor to determine the correct cause and receive appropriate treatment.


Complete blood count testsTrusted Source (CBC) help verify iron deficiency. Still, it is worth noting that the decision on which tests from a wide list to perform should be made by a doctor after reviewing your individual symptom history. A reduced level of this element in the blood is indicated primarily by a low iron level in the serum.


An iron deficiency test often includes an assessment of Mean Corpuscular VolumeTrusted Source (MCV), which measures the average volume of red blood cells.

Zinc and Vitamin C

Check for zinc levelsTrusted Source, as both minerals can affect each other. Vitamin DTrusted Source and iron deficiencies often coexist, and it may be useful to perform liver enzyme tests as the liver plays a fundamental role in iron metabolism.


Other recommended tests may include assessing the level of transferrinTrusted Source, the iron transport protein, and transferrin iron saturation. Sometimes, it is necessary to conduct additional tests to determine the underlying cause of iron deficiency, such as tests for hidden bleeding in the gastrointestinal tract.


People who come to the clinic reporting a lack of iron receive recommendations on supplementation and learn what to eat to prevent iron deficiency in the future. Fortunately, iron is in many food productsTrusted Source – but you need to know what to combine it with and what food combinations to avoid.

Iron Deficiency: What Is, Causes, Symptoms, and Tests

Iron is an essential nutrient in maintaining good health. There are two types of ironTrusted Source supplied to the body with food: divalent heme iron (obtained exclusively from products of animal origin) and trivalent non-heme iron (obtained mainly from products of plant origin). The first mentioned is absorbed much better than the second.

A variety of foods are rich in iron, with red meat being one of the best sources of heme iron, followed by poultry and fish such as tuna, salmon, mussels, and sardines.

Banned Products

When devising a dietary plan, it is advisable to focus on replenishing the body's iron deficiency and avoiding certain foods that may hinder iron absorption. The list of contraindicated products often elicits surprise. It is because such products flush iron from the body:

Although natural methods of iron supplementation are recommended in a healthy diet, if one is clearly iron deficient or anemic, it is essential to follow the recommendations of a physician, who may suggest more potent iron supplements.


If, despite a diet rich in easily absorbable iron, iron deficiency occurs, we should consider taking oral preparationsTrusted Source of this element. It is worth knowing that iron preparations should be taken one hour before or two hours after a meal. If gastrointestinal problems occur (constipation, vomiting, or abdominal pain), they should be taken while eating, or the single dose should be reduced.

When choosing a product with iron, we should pay attention to the ions' content, not this trace element's salts. Moreover, remember not to drink it with tea, coffee, milk, or wine but with juices rich in vitamin C. Do not use its preparations with other vitamins and minerals if you need high iron absorption. They may significantly limit the bioavailability of this element.

Among iron salts, fumarates, gluconates, and sulfates of divalent iron are absorbed better than citrates and sulfates of trivalent iron. Chelates (e.g., iron bisglycinate) are much more bioavailable than the abovementioned compounds.


May 19, 2024
9 minutes read

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