Iron deficiency anaemia (IDA) is a condition I’m sure many of us are familiar with. In fact, IDA is the most common nutritional deficiency in the world, affecting up to 25% of the population, according to the World Health Organisation (WHO). That’s 1 in every 4! With preschool-aged children, pregnant & non-pregnant females as the most affected & men the least affected by IDA.
The most common cause of iron deficiency is, of course, insufficient dietary intake of both heme (animal-derived) & non-heme (plant-derived) sources of iron. However, for a number of individuals, IDA can seemingly become impossible to treat & unfortunately there may be more than just low dietary intake at play. There are a number of other important underlying reasons that may need to be addressed in order to gain any traction with increasing iron levels.

For many, iron deficiency anaemia can be left undiagnosed for far too long due to the non-specificity of symptoms. If you experience any of the symptoms as described below please speak to your trusted health professional about appropriate testing:

What are the most common symptoms of iron deficiency:

  • Fatigue & lethargy
  • Shortness of breath (esp. doing tasks that would normally be easy – i.e. walking up a flight of stairs)
  • Low mood/mental lethargy/lack of motivation
  • Muscles which fatigue/ache quicker than usual
  • Pale “transparent” appearance to the skin
  • Pale lips &/or conjunctiva of the eyes
  • Decreased resistance to infection + slow recovery from infection
  • Brittle hair & nails

Why Do We Need Iron?

Iron is an essential mineral for many processes within the body. These are the main functions of iron:

Oxygen Transport

Possibly the most important function of iron is it’s role in both storing & transporting oxygen from the lungs to the rest of the body. Every single organ system in the body requires oxygen for its function & survival. When the cells are deprived of oxygen their basic function is diminished & the bodies ability to heal & regenerate is suppressed. For this reason, it’s easy to understand why the main symptoms of IDA are fatigue & lethargy, the entire body is trying to conserve energy because it’s not getting enough oxygen to function optimally.

Energy Production

I’m sure most people have heard of the citric acid cycle, one of the most important processes in our body, how we make cellular energy or ATP. The citric acid cycle is dependent on sufficient iron in order to support a number of enzymes which are critical for its function.

Mental Health

Iron is an essential cofactor for the production of a number of neurotransmitters involved in mood & mental wellbeing including dopamine & serotonin.

Thyroid Function

Iron is essential for the production of thyroid hormone. IDA deficiency is commonly associated with hypothyroidism (under-active thyroid) due to irons role in thyroid hormone synthesis. Low iron can also impact selenium concentrations in the body, another essential component of the thyroid hormone picture.


Sufficient iron is necessary for the synthesis of T lymphocytes & production of other essential immune compounds required for helping the body fight infection such as neutrophils. IDA can significantly impair both humoral & cellular mediated immunity, thereby leading to increased susceptibility to infection & reduced capacity to recover. Fun fact: iron is also an important fuel of many infective pathogens, luckily the body has eloquent mechanisms in place to sequester iron out of serum & shuttle it back to storage (ferritin) in order to promote host defence against infection.


Heme-containing enzymes protect cells against the accumulation of hydrogen peroxide, a potentially damaging type of free radical or reactive oxygen species (ROS). Antioxidants protect the body from free-radical damage & premature ageing of the body.

DNA Replication & Repair

A really important enzyme involved in DNA repair called ribonucleoside-diphosphate reductase requires sufficient iron & energy (ATP) to start the first step of DNA replication. The result of poor DNA replication is unfortunately permanent DNA damage. Healthy DNA replication is essential in preventing the onset of a number of chronic health conditions.

Cytochrome P450 Function

Cytochromes are a group of enzymes involved in numerous metabolic processes within the body such as metabolism of vitamin A, D & K, prostaglandins, fatty acids, etc. Cytochromes are also highly involved in the detoxification process of compounds from the body including medications, toxins & pollutants.

Why Are My Iron Levels Always So Low?

Sometimes IDA can seriously overstay it’s welcome, for many of us it can be a continuous struggle to get iron levels up, even with consistent supplementation & dietary inclusion. When treating IDA it is important to uncover some of the reason(s) why this may be occurring, especially when the obvious factors such as sufficient dietary intake & supplementation have been addressed. Here are the most common contributing factors to chronic IDA:

Low dietary intake/malnutrition

Low dietary intake would be considered a primary deficiency, meaning that there is no other medical reason or underlying cause of the deficiency other than insufficient dietary intake of iron. This presentation is, unfortunately, more common of those who practice a plant-based, vegan or vegetarian lifestyle. If this applies to you then increasing non-heme iron-containing foods will be imperative & should correct the deficiency in time. Keeping in mind you may need to supplement for a short period to increase your iron stores, depending on how low they are & then eventually maintain this via diet. If you do engage with a vegan/vegetarian lifestyle it’s always recommended to have your iron checked regularly to assess your status. In most cases preventing iron deficiency is easier than treating iron deficiency.

Heavy Periods

Blood loss from menstruation is a very common reason why many women find it incredibly difficult to maintain robust iron levels. In fact, because of this, women’s daily requirement for iron is 18mg as compared to men who only require 8mg per daily. This can be particularly problematic when a woman experiences menorrhagia (heavy menstrual bleed defined as blood loss of greater than 80mL in total or a period which lasts longer than 1 week) whether due to conditions such as endometriosis, fibroids, sex hormone imbalances, hypothyroidism or other reproductive health concerns. Unfortunately, IDA can also promote further heavy bleeding, thereby worsening the problem & creating a vicious cycle.

Poor Gut Function

When the digestive tract is inflamed for whatever reason this can dramatically influence how efficient absorption of iron will be. Any inflammatory response within the gastric lining may promote malabsorption to occur, reducing the absorption capacity of a number of critical vitamins & minerals including iron. Unfortunately, when there are digestive concerns rarely is iron the only nutrient to be lacking. When multi deficiencies present in combination with digestive abnormalities, gastric pathologies should be investigated.

Gastrointestinal Disorders

Gastrointestinal conditions such as coeliacs disease, Crohn’s disease, ulcerative colitis, irritable bowel syndrome & even other undiagnosed food allergies/intolerance can make it difficult to absorb sufficient iron due to the inflammatory nature of these conditions. Individuals who frequently experience diarrhoea may also encounter low iron due to faster gastric transit times & less capacity for optimal absorption. Other digestive conditions which can impair iron absorption include Helicobacter pylori, chronic parasitic infestations, reflux, peptic ulcers. If you have been diagnosed with a digestive disorder & struggle with IDA please consult your trusted health professional for the best plan forward.

Incorrect Food Combining

There are a number of compounds found in foods & beverages which have been shown to inhibit the absorption of iron. Some even up to 70%!!

  • Phytates, as found in whole-grains & legumes, may have significant iron-binding capacity if not prepared correctly. To minimise phytates please soak & thoroughly rinse these foods prior to consumption.
  • Tannins as found in black tea, coffee & red wine. The research found, in particular, tannins in tea can decrease the absorption of iron by up to 60%, coffee can reduce absorption by up to 40%. If you are supplementing iron, it may be a better option for you to take it in the evening to avoid any unwanted binding from our morning cuppa!
  • Oxalates as found in spinach, chard, chocolate & berries. Blanching or lightly cooking dark leafy greens can break down these compounds, allowing for maximal absorption.
  • Calcium found in dairy products & supplements especially can bind non-heme iron up to 70%. When supplementing iron always take away from calcium-rich foods or supplements.
  • Zinc competes for absorption & is best kept away from iron. This applies specifically to supplementation as zinc & iron in a meal appear to both be absorbed well. Always take zinc supplementation away from iron supplementation

Chronic overuse of NSAIDs (i.e. Nurofen)

This class of medications have been shown to negatively influence gastric function, leading to concerns including irritation to the gastric lining, microscopic bleeding as well as changes to the microbiome. Each of these presentations can have influence over iron absorption. If you are a chronic or consistent user of these medications please consult with a qualified health professional about alternatives if they are available to you.
As you can see there are a number of reasons why you might have persisting low iron. If you have been experiencing chronic low iron it’s so important that these underlying concerns are addressed correctly by a qualified health care practitioner.
To book a consultation with a Naturopath or Nutritionist please follow the link here.
References available upon request

Mindy Duncan is a Bachelor qualified clinical naturopath with special interests in women’s health, menstrual & hormonal health, thyroid function & self-esteem. Mindy is available for consultations via the Vive Clinic on Tuesday & Wednesdays.

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