Iron deficiency and iron deficiency anemia in children and adolescents

Iron deficiency and iron deficiency anemia in children and adolescents

Iron is one of the most important minerals in the human body and has many different jobs that are essential for the development of children and their health, both in the short term and the long term period.

Iron deficiency and anemia (notice how these are two different things and it is really important to be able to distinguish between them), are very common in all the different populations of children and their different ages, from infancy to adolescence.

To put it simply, about 8-14% of children in the world under the age of 4 years have iron deficiency, and about one third of these proceed to develop anemia due to iron deficiency.

So, iron is an important topic and the aim of this chapter is to present to you all there is to know about consumption of iron throughout childhood and the different ways in which we are able to recognize and deal with iron deficiency, anemia and that which is in between.

Why is iron so important for children and adolescents?

Iron has several different important jobs. One of the more important jobs it has is the production of the hemoglobin molecule that is found inside our red blood cells. Hemoglobin carries oxygen around our blood and takes it from our lungs to all the organs in our body.
At the first stages of life, iron is also responsible for the proper development of the different systems in our body, for example: the nervous System. Therefore, iron deficiency may lead to a delay in the normal development of different systems in our body.

In addition, iron has a central and important role in the process of energy production and metabolism of different products in our body, in the proper functioning of the immune system, in temperature regulation, and so forth.

What is the difference between iron deficiency and anemia due to iron deficiency?

These two are continuous processes.
Iron deficiency – the total iron content stored in the body is low, but there is no anemia (hemoglobin is normal).
Iron deficiency anemia – the low iron stores in the body are unable to produce sufficient hemoglobin which leads to hemoglobin deficiency, i.e anemia. In children (and adults), it is better to avoid and correct both of these situations.

How much iron do children need to receive?

Children need to absorb 1 mg of iron per day.
Despite that, iron is not readily absorbed and only about 10% of the iron that children consume is actually absorbed. This means, children need about 8-10 mg of iron per day to be able to absorb all the iron they need every day. Infants that feed on formula (or even those that breastfeed, where iron absorption is better), are unable to reach this level of iron consumption. This is the reason behind the current iron supplement recommendation for children under the age of 1, in some countries, as explained below (you can read more here).

What is the function of iron at the different stages of childhood?

The body’s requirements for iron vary along the years of childhood.
As per usual, it all starts with the mother. When the fetus is in his/her mother’s womb, they receive the amount of iron needed for this stage of life through their mother and store the remainder for future use. Usually, the iron stored is sufficient to last the newborn from birth till around 4-6 months. Afterwards, the iron stores found in the infant’s body begin to decrease. This is also a period of time when the child’s growth accelerates, and their weight increases three or more times as much in a relatively short period of time. At the same time, the child’s blood volume increases and the rate at which hemoglobin needs to be produced to meet the body’s demands increases. Without significant enhancement of the iron consumption, the body could reach a stage where it is unable to produce sufficient hemoglobin, and the deficiency that could develop may determinately affect the child’s health and development.

This gap, between the accelerated growth and the insufficiently available iron, characterises other advanced stages in childhood as well. Another such stage is adolescence, when the risk of developing iron deficiency increases significantly, due to the same exact reasons where supply is unable to meet demand. Adolescent nutritional habits, which are often insufficiently diverse, such as veganism or vegetarianism without proper nutritional accompaniment or weight-loss diets without proper observation, or obesity and excessive physical exercise – all of these can cause that same gap between supply and demand in iron and lead to iron deficiency anemia.

In female adolescents, the monthly menstrual cycle can bring about significant loss of blood (and iron of course) and so iron deficiency and anemia due to iron deficiency are very common in adolescent females.

What are the signs of iron deficiency in children?

One should remember that anemic children are usually asymptomatic. Despite that, the lack of iron determinately affects the child’s health and his development in various ways, both in the short term and the long term.
Iron deficiency is related to abnormalities in the development of the nervous system and can bring about a cognitive decline when there is a long-running deficiency. Older children may experience learning difficulties, which is also a result of a decrease in alertness or attention and concentration capabilities due to the deficiency. Iron deficiency is also related to different types of episodes such as breath-holding spells (you can read more about this here), restless leg syndrome, etc.
When there is a reduction in the levels of hemoglobin and anemia, the most common symptoms include pallor, intolerance to cold, weakness, fatigue, sometimes episodes of syncope or pre-syncope, difficulty breathing on exertion and an increase in heart rate (and cardiac insufficiency in extreme cases).
One of the major difficulties with symptoms due to iron deficiency is that it is very “easy” to relate them to other issues, that do not necessarily have anything to do with the iron metabolism of the body. The children, and often their parents too, treat these symptoms as part of larger natural and inevitable phenomenon, such as adolescence, and assume it is part of the hormonal imbalance that characterizes this time period. Parents therefore do not seek medical attention when their child experiences symptoms such as learning difficulties or fatigue.

How can anemia and iron deficiency anemia be diagnosed?

Through appropriate blood work.
In some places in the world, it is recommended to perform infant blood work around the age of 9 months to screen for anemia. But, as I will be mentioning below, simple blood tests are able to show the level of hemoglobin and only indirect clues about iron deficiency.
After this age, screening is not carried out routinely, and it is up to the parent who suspects their child might be suffering from anemia to seek medical attention and “convince” their physician to order blood work for their child.

What are the blood tests required for workup of iron deficiency and anemia due to iron deficiency?

Complete blood count – a test that can be carried out together with other tests (venous sample) or on its own (finger prick, as performed on babies).
As I’ve mentioned previously, the red cell lineage takes up the most space in a complete blood count report, and you can read all about complete blood counts in the following link.
There are several parameters in the complete blood count that cause a pediatrician to raise a concern for iron deficiency or anemia due to iron deficiency.
Hemoglobin / HGB / HB – the most important parameter related to the red cell lineage. Normal values vary depending on age and gender. However, if the value is lower than the defined normal, then your child has anemia. Is it due to iron deficiency or not? We’ll learn more about this below.
Red blood cells/ RBC – the number of red blood cells. In cases of iron deficiency both the hemoglobin and the RBC values will be lower than normal.
Hematocrit / HCT – this is actually another way of looking at hemoglobin. In practice, this is the volume percentage of red blood cells in blood. A low value indicates anemia
Mean Corpuscular Volume / MCV – this is a very important parameter concerning anemia due to iron deficiency. In cases of iron deficiency, this value will be low. Values that are lower than 70 in babies around the age of one may indicate iron deficiency (with or without anemia).
For the next few blood tests, a venous sample is required together with a few more test tubes beyond the one needed for the complete blood count:
Iron – nice and straightforward. This test shows the level of iron in the blood. If its low – the child has iron deficiency. If it’s normal – then there is no iron deficiency.
Ferritin – this is the most accurate test for assessment of stored-iron levels. When ferritin is low, iron deficiency is present. Very important though – ferritin is also an inflammatory marker, and it could be high even in cases of iron deficiency. An experienced pediatrician will be able to identify such cases, and will know when to expand the workup to search for a source of inflammation if needed.

There are several more tests that are related to iron metabolism in the body, such as reticulocyte levels and transferrin. These will be carried out in cases when further workup is needed.

Another test that is an absolute must when iron deficiency is observed in a child (or adult) is one for Celiac’s Disease (gluten sensitivity) which has a prevalence of about 1.4% in the general population in the world these days. I’ll also share with you, from my own personal experience, that even if the first serology testing for celiac is negative at a very young age, it is worthwhile repeating the test in the future when it is still highly suspected, especially in those suffering from iron deficiency anemia under the age of 12 years. After 12, if the serology testing is negative, the chance of actually have Celiac’s Disease is very low. I suggest you read more about Celiac here. Okay, let me just say this one more time to make it even clearer: one should never diagnose iron deficiency anemia in children without checking for Celiac’s Disease.

What should I do if my child has been diagnosed with iron deficiency, with or without anemia?

If your child was recently diagnosed with iron deficiency, you need to see your primary care physician and try to figure out the reason behind the deficiency together. Remember that it could be due to insufficient nutritional iron intake, iron absorption difficulties, or due to loss of iron, such as through bleeding.
The doctor should take a full history and ask about your child’s eating habits, examine your child meticulously and consider further workup for other reasons that could explain your child’s deficiency (have I mentioned Celiac’s Disease already?).

If a gastrointestinal problem is suspected (absorption difficulties or bleeding), your pediatrician will refer you to a gastroenterologist.

Adolescents that have heavy menstrual bleeding can be referred to gynecologist where pharmacological therapy reduce the bleeding may be considered.

How can we prevent and treat iron deficiency in babies and children?

When it comes to babies, let me remind you a little about breastfeeding, which amongst all its advantages also allows for better absorption of iron. To read more about the advantages behind breastfeeding (as well as the difficulties) refer to this link here.
Beyond this age, for every other stage of our lives, it is important that our daily dietary intake includes diet that is rich in iron.

What foods are high in iron?

Some of these include:
– Meat – mainly beef and turkey. Chicken contains much less iron. Internal organs, such as liver, are rich in iron.
– Different types of fish.
– Green vegetables, such as spinach and kohlrabi.
– Different legumes, including dried beans, lentils, chick-peas and peas.
– Iron rich cereals.
– Tahina.
– Beetroot.

As the years pass by, children tend to become more and more picky about their food and the iron-rich foods suggested are not always amongst their top selection. Parents should try to be patient, determined and sometimes, also creative. If your child refuses to eat a certain food that is known to be rich in iron once, twice or even three times, try not to give up. Sometimes, small adjustments to the way the food tastes or looks could go a long way and cause them to give it a shot after all.

Another important point to remember is that some foods are known to decrease the absorption of iron in the body.
Consumption of iron with fruits and vegetables that are rich in Vitamin C (such as citrus juice or green salad) are strongly recommended.
On the other hand, taking iron supplements (or iron-containing food) together with dairy products or products that are rich in caffeine (such as tea) may decrease their absorption.

What about iron supplements?

If you have identified a deficiency (or anemia, of course) and if the change in dietary habits did not make any difference (which is what happens for most cases of severe deficiency or anemia), iron supplements are then advised for a period of 3 months.
These supplements can be taken by mouth (drops, syrup or tablets) or in more severe cases, intravenously.

How much iron should be taken as supplements?

In cases of iron deficiency, with or without anemia, and once you’ve seen your doctor and have made a joint decision to treat with supplements, a quantity of 3-6 mg per kg of body weight (the usual dosing is 5-6 mg/kg) is recommended. The upper daily limit is 150 mg (most patients will not receive more than 100 mg per day).
So, a child who weight 15kg will need about 90 mg of iron per day.
If the quantity is large, it can be divided into two doses per day.

What are the side effects?

The only side effect is constipation.
From my experience, it is a side effect that is more often talked about than actually experienced in practice, especially when it comes to children.
The dose can be divided so that it is taken twice daily and an increase in the consumption of dietary fiber can be made to overcome this (read more about this under constipation). I think the advantage of treating the anemia is much more significant than the disadvantages behind the side effects.

How long should one be treated for with iron and is there a need for repeat bloodwork?

The length of time for treatment will be decided upon by the doctor depending on the severity of the anemia and the response to treatment.
There is an obvious need to repeat blood work after a certain period of time, usually several months after beginning treatment. The goal of the repeat test is to make sure that the parameters of deficiency have improved.
In addition, if there are tests that were not performed during the initial diagnosis, they can be carried out at this time.
Remember that it is important to continue treatment even after the parameters have improved in order to “fill up” the iron stores in the body.
If the parameters and values do not improve, despite having taken the iron supplements properly, your pediatrician should consider other possible diagnoses and expand the workup.

To conclude, even though it is iron we’re talking about, this isn’t a very hard topic.
Remember that iron is very important for proper health and childhood development.
Make sure to give your babies their iron supplements as needed.
And make sure your children consume food that are high in iron throughout their childhood years and be aware of signs and symptoms of deficiency that require a simple blood test for diagnosis.

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