Iron. What is it? How does our body use it? Why is it so important for girls?

What is it?

Iron is an essential mineral for us human beings and it is estimated that 1/3 of the world population is deficient. Iron is a vital component of haemoglobin (the red in red blood cells) which is used to carry oxygen and carbon dioxide to and from cells, is used in neurotransmitter production, energy production, immune system maintenance and DNA and collagen synthesis. It also has other roles in the body but my point is that iron is essential for human life. As with everything it seems, you can have too much of a good thing. Iron is also inflammatory so, your body, in its infinite wisdom, has systems in place to protect you against excess iron intake.

Did you know that when you ingest foods (or supplements) containing iron that the cells lining your digestive tract absorb that iron, or not. If they decide to absorb it they hold onto it. They keep very careful control of it and only release it into the blood stream in the amount needed. The cells that line our digestive tract are sloughed off every three days and excreted in our stool so if you have not needed that iron in the 3 days since you ingested it then it will end up in your loo.

Haem or non-haem, that is the question.

Iron from food sources comes in 2 forms, haem iron, which comes from animal products, and non-haem iron, which comes from plant based foods. Our bodies use haem iron as it is and are able to absorb it directly. Non-haem iron is in an oxidised state and needs to be reduced (by vitamin C) before your body can absorb it. This is why it is advised that vegetarians eat iron rich foods with vitamin C rich foods. If the non-haem iron and the vitamin C are not in the intestine at the same time the intestinal cells will not open their iron receptors to the non-haem iron and it will be excreted.

Absorption of either form of iron is dependant on enough stomach acid, a healthy intestinal lining, and other biochemical variabilities. So, low iron levels may indicate an issue in the digestive process if dietary levels appear to be adequate.

Phytochemicals in plant sources of iron such as phytic acid can interfere with iron absorption as can other minerals and partially digested protein in the digestive tract. So what you eat with your iron rich foods matters.

Iron rich foods and their levels

When comparing animal and plant forms it is important to understand that haem iron has a much higher absorption rate than non-haem iron, 10x higher. The following chart is a sample of foods containing iron and the levels they contain.

Other factors effecting iron levels

Young women who have just begun menstruating will find their recommended daily intake for iron jump from 8.7mg/day to 14.8mg/day, 3.5mg/day more than their male counterparts. That is the same as 100g more lean beef or an 80g portion of dried prunes everyday. It is important to know and understand this if you are a parent of a young woman, responsible for menu planning for adolescent girls or are an adolescent girl yourself. These numbers are general. If you have heavy periods you will need an even higher level of dietary iron. Iron deficiency anaemia is a common problem worldwide among adolescent girls and a large proportion of adolescent girls who do not have anaemia fall into the insufficient range. Menstruating people need more dietary iron than non-menstruating people so should be eating a different diet. Does your adolescent girl eat a different diet than her brothers or male peers? Does her school offer a different menu or additional iron rich foods for menstruating people? How do you know she is getting her daily recommended intake?

Is iron really the issue?

Low levels of vitamins such as B12 and folate can create symptoms similar to low iron and can even change blood markers similar to low iron. It is important to have a full blood count, full iron panel and folate levels all tested if you or someone in your life is struggling with low iron symptoms.

What are the symptoms of low iron?

Symptoms of low iron include, fatigue, pale skin, metal health issues such as lack of motivation, depression and anxiety, decreased immune function, learning disabilities, increased blood glucose levels, impaired growth, restless leg syndrome and recurrent infections.

Should I supplement?

In a word, no. No one should take an iron supplement unless under supervision of a qualified professional. Iron can be inflammatory and toxic, which is why your body keeps it under such tight control. Once inside the body there are mechanisms of storing iron but not great ways to excrete it so it is possible for iron to build up to toxic levels. If you think you may be low in iron I would recommend seeing a nutrition professional to have your levels thoroughly tested and your diet analysed. If it is decided that supplementation is right for you, you should have your blood tested every 12 weeks to monitor progress carefully. If you have an infection of any kind, in any area of your body, cease any iron supplementation. Iron feeds many microbes and your body has protection mechanisms in place to ‘hide’ any iron from infecting microbes. If you are supplementing while you have an active infection you are putting yourself at risk for toxic levels of iron to build up quite quickly.

As a nutritional therapist I can order private blood work and can interpret it for you as part of your consultation to help you unlock what is happening in your body. If you would like more information about your life stage nutritional requirements or those of your family members please do get in touch. Knowledge is power.

To wellness!


Want to learn more about iron, what it does in your body and the current state of of our intake? Check out the links below.

Iron in infection and immunity

Impact of menstrual blood loss and diet on iron deficiency amount women in the UK

Iron overload in thalassaemia: different organs at different rates

A systems biology approach to iron metabolism

How we diagnose and treat iron deficiency anaemia

Iron deficiency and other types of anaemia in infants and children

The effects of vegetarian and vegan diet during pregnancy on the health of mothers and offspring

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