Iron Testing 101

young girl with her mother as a smiling doctor performs a checkup on the girl

By Caitlyn Vanderhaeghe, B.A., B.Ed.

Iron is an essential mineral that is needed by our bodies to create red blood cells and supply oxygen to every cell. Iron’s important role in brain development makes it especially important for babies and children.

Iron deficiency is the most common nutrient deficiency in the world, and Canada is no exception. Iron deficiency and iron-deficiency anemia can cause serious health issues such as lowered immunity, brain abnormalities, and behavioural problems.

Symptoms of low iron can be difficult to spot, especially in newborns and babies. By the time symptoms show up, iron is already deficient and can cause health problems for your child. An iron test can help to confirm an iron deficiency.

If you know you had low iron or anemia during pregnancy, then it is important to monitor your baby’s iron levels to ensure they do not have low iron or are suffering from iron-deficiency anemia.

The following six symptoms are good indicators that your child may be iron deficient and needs an iron supplement.

The Top 6 Symptoms of Low Iron in Toddlers and Children

  • Behavioural problems, frequent tantrums, and meltdowns
  • Pale skin and dark under-eye circles
  • Hard time falling asleep and unhappy when waking up
  • Frequently sick
  • Craving/eating ice or dirt
  • Poor grades, learning difficulties

If you suspect your child has low iron, make an appointment with your physician. The doctor may recommend iron testing.

Common Blood Tests for Low Iron

A complete blood count (CBC) test will check the levels of red and white blood cells including hematocrit, platelets, and hemoglobin. A CBC blood test will also check the size of red blood cells. In those with iron-deficiency anemia, the red blood cells are typically smaller than those found in people who are not anemic.

Testing hemoglobin alone is not ideal as it will only show iron deficiency anemia, which occurs long after iron deficiency has begun. Therefore it is important to get ferritin levels checked as well. The ferritin test measures the level of ferritin in the blood. Ferritin is the protein that stores iron in the body. If ferritin levels are low, then it means the body’s iron reserves are very low.

Below is an example of what your child’s test results may look like. Results may vary depending on where you live and the types of tests ordered by your doctor. 

Did You Know?

Ferritin is the protein that stores iron in the body. If ferritin levels are low, then it means the body’s iron reserves are very low.

The Pros Outweigh the Cons of Testing Children’s Iron

Some parents may not want to have their child’s iron levels tested because they are afraid of needles or do not want to subject their child to a painful experience. The truth is, the lasting consequences of an untreated iron deficiency are far worse than a trip to the doctor and a needle prick. The faster an iron deficiency is addressed, the less the child’s long-term health will suffer.

How to Support your Child if They Need a Blood Test

Understandably your child may be afraid or nervous about getting a blood sample taken especially if you also have a fear of blood tests.  To ensure a good experience, adopt some of the following recommendations:

  • Do not draw too much attention to the blood draw appointment – your child doesn’t need to worry for a week before the appointment time.
  • Stay calm and try to avoid putting any worries you have on your child.
  • Do not lie – if your child asks if it will hurt, tell them it is a little pinch. If you lie and say it doesn’t hurt, they will not believe you next time.
  • Dehydration can make it harder for the nurse to find a suitable vein so make sure your child has had lots to drink before the blood test.
  • Request a nurse who is experienced with children or go to your local children’s hospital. This will ensure the experience is positive.


How a Blood Test is Done

Some blood tests can be completed by a simple finger prick, but if more than one test is required, your child will have blood drawn from his or her vein, most commonly from the arm. 

Pain and Discomfort During the Test

Your child may experience some pain and discomfort when the blood is drawn, like a sharp prick, and there may be some slight bruising and tenderness at the site for a day or two afterward. You can ask your health care provider or call ahead to the testing lab to see if a numbing patch is available. Apply 10 minutes prior to the blood test to prevent pain from occurring. To reduce bruising ensure you apply firm finger pressure to the site for a few minutes or so after the blood is drawn. Bruising happens when blood leaks from the vein that was punctured for the blood test to the tissue under the skin.

child with a strap around her upper arm, waiting for a blood sample to be taken

Where to Take Your Child for the Test

If you live close to a children’s hospital check to see if they have an outpatient lab. The lab technicians routinely work with children and are very experienced at taking blood from children making the experience less traumatic. Call ahead and speak with a technician if you have a child with any special needs to ensure that there is someone there to help you and your child.

If you do not live near a children’s hospital, contact your nearest lab (for example, LifeLabs) and ask if they have someone who works with children and book an appointment with them.

young child playing with a koala bear stuffie and toy doctor's equipment including plastic stethoscope, blood pressure cuff, and syringe

Waiting for Results

Results usually take two business days or less. Depending on the age of the child and your location you may be able to view your results online. Ask the lab prior to your appointment in case you need to sign up to receive online results.

Reading Your Results

All test results will be provided alongside a reference interval (previously known as range of normal). Some reference ranges may be very broad. This is true with iron testing, as the reference range is quite large for hemoglobin and ferritin. Many people will start to see symptoms of low iron and iron deficiency long before a test diagnoses them with anemia.

The ranges will let you know if your child is anemic, however non-anemic iron deficiency, which is much more common, is also a serious health problem and can cause lasting issues, especially in the very young.

Because our current reference ranges are so broad, it means by the time your child is at the low end of the range they have been suffering from low iron for some time.

As stated in The American Journal of Clinical Nutrition (Volume 106, Issue suppl_6, December 2017), the early stages of an iron deficiency are concerning and the goal should be prevention, instead of trying to correct the issue after the fact.

“First, anemia is the final state in iron depletion. Thus, the developing brain is already iron deficient when iron deficiency anemia is diagnosed owing to the prioritization of available iron to red blood cells over all other tissues during negative iron balance in development. Second, brain iron deficiency, independently of iron deficiency anemia, is responsible for long-term neurological deficits. Thus, starting iron treatment after the onset of iron deficiency anemia is less effective than prevention.”

American Journal of Clinical Nutrition

The lower your child’s ferritin levels, even when they are within the normal reference range, the more likely they are to be deficient. If your child’s iron test result shows a deficiency, iron supplementation is required, as well as a diet with adequate iron intake. Ideally, have your child return for testing every three months until iron levels are optimal.

The BC guidelines regarding ferritin levels are as follows:

Sex and Age Reference Range
Males and Females: younger than 6 months 31 – 1454 ug/L
Males and Females: 6 months to 1 year 19 – 401 ug/L
Males and Females: 2 to 5 years 12 – 224 ug/L
Males and Females: 6 to 14 years 31 – 177 ug/L
Females: 15 to 18 years 12 – 152 ug/L
Males: 15 to 18 years 28 – 186 ug/L

Health Canada’s guidelines for hemoglobin levels by age are as follows:

Age (years) Hemoglobin Concentration (g/L)
1 to <2 110
2 to <5 111
5 to <8 115
8 to <12 119
Males 12 to <15 125
Females 12 to <15 118
Males 15 to <18 133
Females 15 to <18 120

Normal is Not Always Normal

If the range is 12 – 224 ug/L, then having a result less than 50 ug/L would not be good;
it is still within normal, but it is low normal.

Iron deficiency is a serious health concern for children of all ages that can be hard to spot or monitor without blood testing. To avoid lasting health problems, have your child’s iron levels tested. Support your child’s iron intake with supplementation and diet.

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About the Author

Caitlyn Vanderhaeghe, B.A., B.Ed., is a health advocate, licensed teacher, and CEO of KidStar Nutrients. Caitlyn’s experience spans more than a decade of supply chain and ingredients sourcing in the natural products industry. As a mother of three daughters, Caitlyn’s mission is to help educate parents about kids’ nutrition and provide clean nutrients for kids and families.