Iron Deficiency - All your questions answered!
With virtually all media attention on COVID-19, for THIS post, I’ve made a choice to continue on discussing the various aspects of nutritional/naturopathic medicine that I would usually be blogging about.
Please know that I’m not ignoring the pandemic, I’m just adding some normality to the noise, and sticking to business as usual whilst acknowledging that we are in very unusual and challenging times!
Iron is one of those nutrients I get asked about ALL the time. So, I thought I’d put all the answers to commonly asked questions in one place. Hopefully you find it helpful.
Iron deficiency is the most common deficiency globally – affecting 33% of the world’s population. It's prevalent in both developed and developing countries. Iron is also a transition metal, which means it can act as both an antioxidant and an oxidant. This is part of the reason there is so much debate and controversy around iron... it has two faces!
Who is most at risk of deficiency?
Young children, adolescents during growth spurts, menstruating women, anyone experiencing excessive blood loss, athletes, vegetarians, vegans, the elderly (with co-morbidities/ on polypharmacy) and those with gastrointestinal inflammatory diseases who are at risk of malabsorption.
Generally, one or more of these three things cause a deficiency:
1. An imbalance between iron intake and iron needs (i.e. during periods of growth, plant-based diets, athletes)
2. Blood losses (i.e. heavy menstruation)
3. Malabsorption (i.e. coeliac disease, helicobacter pylori infection, or autoimmune gastritis)
What are the symptoms of Iron deficiency?
Iron is heavily involved in oxygen transport via red blood cells (with Iron being at the centre of the haemoglobin molecule), is a critical enzyme co-factor, is part of myoglobin (which helps store oxygen in muscles), and is required to fight infection.
So, if someone is lacking iron, many of the symptoms will include:
Low immunity/ recurrent infections.
Fatigue – low physical and cognitive energy
Weakness
Headaches
Dizziness
Shortness of breath
Pallor
Poor circulation
A craving for ice and/or pica (craving for non-foods – like hair, dirt, and paint chips)
Restless legs
Hair loss
Oral manifestations: dry mouth, sore/swollen tongue
Is ‘Low Iron’ or ‘Iron Deficiency’ the same as ‘Anaemia’?
No. Anaemia refers specifically to low haemoglobin, which can occur with or without low iron. In other words, an iron deficiency isn’t declared anaemia unless haemoglobin levels are low alongside other iron parameters.
Is Iron absorption straightforward?
Not really. In large quantities iron can be toxic, which is why the body actively regulates iron absorption. Iron occurs in two forms in foods: haem (animal foods - red meat and organ meats especially) and non-haem (plant foods such as legumes, grains, green leafy vegetables and dried fruits).
Absorption from non-haem sources found in plants is exceedingly less efficient than absorption of haem-iron found in meat. Although the ‘average’ person (who is iron replete) absorbs less than 15% of the iron they consume, there is HUGE variability in how much we can absorb.When it comes to supplements (which is the non-haem form), healthy people with good Iron stores will absorb between 2-13% of the supplemental dose of Iron they take. In people with reduced Iron stores however, absorption increases to between 5-28%.
When you consider the enormous doses of Iron some supplements contain (like Ferrograd C, which contains a whopping 105mg of elemental Iron per tablet) is about 10 times what’s found in the average Western diet, and only a minor fraction (no more than 10–20%) of a high dose iron supplement is effectively absorbed (1), it begs the question, what's happening to the 70-80% of iron that doesn't get absorbed?!?
Accumulating evidence indicates the excess/unabsorbed Iron enters the colon and causes unwanted side effects at the microbiota level (2), and has a correlation with intestinal inflammation (3).
In addition to this, high dose oral iron is frequently associated to adverse effects, which mainly present in the gastrointestinal tract (such as nausea, vomiting, heartburn, epigastric pain, constipation, and diarrhoea). These adverse effects are likely due to direct toxicity of unabsorbed iron on the intestinal mucousa (3).
Knowing this, what is the ideal supplemental dose and form of iron, and when it is best to take?
With iron, doses matter more than form (i.e. sulfate vs amino acid chelate), with doses of up to 40mg being best. Remember, at elemental doses over this, there appears to be poorer uptake from the gut, and a greater chance of negative side effects.
The highest bioavailability is first thing in morning, or at night with a meat-based meal. Vitamin C-rich foods will also improve iron uptake, and taking iron 24-48 hours apart seems to be best in regards to uptake, with alternate day being shown to be effective (1).
If you’re an exerciser, and have been prescribed supplemental iron, the best time to take it is within an hour of exercising to ensure adequate uptake from the gut.
What interferes with iron absorption?
Phytates found in cereals, grains, legumes, nuts
Tannins found in tea and coffee
Calcium rich foods, and calcium supplements
Certain medications, like PPIs (protein pump inhibitors)
Overall though, the foods mentioned above have a limited effect long term unless you already have an iron deficiency, in which case being aware of the above interactions becomes much more important.
Who needs to be careful with iron supplementation?
Anyone who doesn’t need it due to already having adequate iron levels (this includes during pregnancy!); people with haemochromatosis; or anyone with an active infection, severe gastrointestinal inflammation or significant microbiota damage.
Iron overdose is a leading cause of accidental poisoning in children (4), so please keep your supplements out of reach of little ones. If your child requires iron, ensure you’re being advised by a professional on the correct dose and monitor levels closely through regular blood tests.
How is best to prepare for a blood test?
Before going for a blood test to assess your iron status, fast for between 5-12 hours beforehand and avoid intense exercise for 24 hours prior. If possible, having your iron studies (which includes transferrin, transferrin saturation, serum iron, ferritin) and done alongside some commonly tested inflammatory markers (such as C-Reactive Protein/ CRP) will help with interpretation.
Finally, there is surprisingly a lot to take into account when interpreting iron parameters on pathology results, so please make sure you're showing your test results to someone who can properly interpret them!
