How to prepare for the blood test for iron? What can affect the performance?

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Blood test

Iron is considered one of the most powerful substances in human blood. It is an integral part of hemoglobin. This element is involved in the formation of blood. A sufficient level of iron in the body is necessary to ensure the process of its connection with the blood protein, the transfer and distribution of oxygen in the circulating blood. This substance enters the body with food, and after the intestine absorbs it, the element spreads through the vascular system. Reserves of iron in the human body are stored in the bone marrow, liver and spleen.

Blood cells

To maintain the proper index of iron, it is necessary to eat properly foods rich in this element: meat and fish dishes, offal, eggs, beans, cereals, fruits and vegetables salads. The need for a woman's body in this substance is twice as high as that of men. This is due to menstrual cycles, in which the girls lose blood together with hemoglobin. At pregnancy or natural feeding of the newborn the norm of iron becomes more. A sufficient amount of it is required by the developing organism of the child.

Excessive maintenance or lack of substance is determined by the analysis of blood on iron. Any deviation leads to negative consequences, especially if the reduction or excess increase in iron is chronic.


  • When a biochemical blood test for iron is prescribed?
  • General information
  • Preparation for analysis
  • Rates of iron in the blood
  • Need for iron
  • What can affect the performance?
  • Why does the indicator exceed the norm?
  • Why does iron decrease?

When a biochemical blood test for iron is prescribed?

To examine the blood, you need to take a sample from the vein. Blood analysis "iron" is prescribed in such situations:

  • Suspicion of intoxication with iron-containing substances.
  • It is necessary to identify the presence of shortcomings in the daily menu.
  • It is necessary to diagnose different types of anemia.
  • When detecting infectious diseases of any form.
  • With a lack of vitamins in the body or hypovitaminosis.
  • If there are pathologies of the digestive system.
  • In order to determine the level of treatment effectiveness.

The highest value of iron in the study is noted in the morning. And in order to get correct results, the test is delivered in the morning. The patient should come to the laboratory on an empty stomach. Before donating blood you can not eat 12 hours. For the chemical analysis of iron in the blood, the colorimetry technique is used. It accurately reveals the content of elements in the blood, and holding is not difficult.

General information

Iron in the human body is deposited in the form of a protein called ferritin. This component is absorbed from the incoming food, and then it is transferred by transferrin - another protein synthesized in the liver. Elements of iron are required for the formation of erythrocytes. The substance is present in the muscle protein - myoglobin and other enzymes.

The iron norm in an adult is 4-5 grams. Approximately two-thirds of the amount - iron elements in hemoglobin. And the rest of the substance accumulates in the tissues in reserve in the form of hemosiderin and ferritin (protein compounds contained in the liver). Despite the fact that ferritin in the blood is in low concentrations, the indicator provides an opportunity to judge the iron reserve in the human body.

Transport of iron

If a lack of iron develops, for example: with a reduction in food, where it is present, or with frequent losses of blood, the body spends its supplies from tissues. The level of ferritin at this time is significantly reduced. If the indicator remains low for a long time, it leads to acute anemia.

Important! The value of ferritin can be lowered long before the appearance of the first signs of low hemoglobin and anemia.

What does a chemical blood test show for the amount of serum iron? The binding capacity of blood serum is considered one of the important functions of blood. The indicator makes it possible to determine the number of iron elements that can transfer blood.

If the body lacks iron elements, then the amount of transferrin increases. This protein comes into contact with iron in the serum. This indicates an increase in the number of free transferrin, and with it, the iron-binding properties of the serum. And when the level of iron elements is exceeded, this ability is reduced, since there are practically no free transferrin.

The parameters of the serum iron in biochemistry change on different days and even throughout the day. This can be checked on the rapid tests. However, the binding capacity of the serum remains at the same level.

Preparation for analysis

Before you take the test for iron, you need to prepare with recommendations:

  • For 12 hours before taking blood, you should not eat (clean water without gas is allowed).
  • Do not allow emotional stress for a couple of hours before visiting the laboratory.
  • An hour before the test is not allowed to smoke.

Rates of iron in the blood

There is a table of norms in vitro:

  • For a child up to a year - from, to 1, mkmol / l.
  • At children from one year till 14 years -22 mkmol / l.
  • In adult girls older than 15 years -3, μmol / l.
  • In men older than 15 years - 1, -3, umol / l.

In the human body, the content of iron elements is small. Norms depend on the weight of a person, sex, height and age, t hemoglobin concentration in mmol / l or in μg per liter. The interpretation of the research data takes into account all the factors.

Need for iron

If the blood deficiency of iron, then this is the reason for reducing hemoglobin and the development of anemia. This disease leads to dangerous pathologies:

  • The protective immune function decreases.
  • Development and growth are delayed in children.
  • Increases fatigue.
  • The skin acquires a pale shade, is scaly.
  • Dyspnea appears and the pulse increases.
  • Failures in the work of the stomach, intestines and thyroid gland.
  • Appetite disappears.
  • Muscle hypotension occurs.

The cause of iron deficiency may be inadequate or unbalanced nutrition. A person needs to constantly replenish losses of iron components, adding to the menu the products in which they are present. Be sure to eat meat, offal and fish, dairy products and eggs. Important vegetable sources of iron elements are fruits and vegetables. Assimilation of this substance helps and other important trace elements, for example: chlorine, calcium, potassium, magnesium and phosphorus, which come with food.

What can affect the performance?

The analysis of "iron in the blood" can be influenced by factors:

  • Daily fluctuations (in the morning time the indicator is minimal, and in the evening it is maximum).
  • Sex - in women, the content of the element is 20 percent lower compared to men.
  • The presence of bleeding reduces the value.
  • Reducing the concentration of protein in the blood will decrease the indicator.
  • The lack of copper can lead to a decrease in the level of iron-containing substances.
  • The use of contraceptives based on hormones (increase the rate).
  • Hemolysis of a blood sample in a container can mean false results.
  • Taking drugs against tuberculosis, chloramphenicol will lower concentrations.

Why does the indicator exceed the norm?

Iron can increase in the blood if a person consumes a lot of iron-containing foods, for example: during diets. This is possible with uncontrolled use of drugs to increase hemoglobin.

The analysis on iron can give the overestimated parameters if in an organism the exchange of iron components is broken. It is possible to develop a disease such as hemochromatosis, when iron is not eliminated from the body properly.


Why does iron decrease?

The causes of iron deficiency pathologies can be:

  • Frequent donation of blood.
  • Chronic blood loss in the digestive system.
  • Posthemorrhagic anemia.
  • Too strict diet and vegetarianism.
  • Starvation.
  • Period of bearing and feeding.
  • The child has accelerated sexual development and growth.
  • Postoperative condition.
Proper Foods

To treat iron deficiency, you need to balance the diet, take iron-containing medicines, vitamins (C and B12), nutritional supplements. At too high rates, treatment in a diet that limits the amount of foods with high iron concentrations. In extreme cases, a blood transfusion will be required.

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