Are you feeling tired and weak? Are your hands cold, your face pale? Well, of course, you might say. It is November, after all. The bleak mid-winter. The season, however, may not be the reason.
Iron deficiency is the world’s most common nutritional deficiency, affecting an estimated one billion people, or a third of us. In the UK, at least, it seems to be on the rise.
At the end of last year, NHS data revealed that hospital admissions resulting in a diagnosis of iron deficiency more than doubled from 2013-14 to 2022-23 while a study from the University of Leeds found that overweight or obese children and young people are at significantly higher risk.
That deficiency can lead to serious health problems, suggested research supervisor Prof Bernadette Moore: “Iron status may be the canary in the coalmine, but the real issue is that prolonged inflammation leads to heart disease, diabetes and fatty liver.”
What is iron?
Iron is an essential trace mineral, essential for our bodies’ production of haemoglobin, the protein in red blood cells that transports oxygen throughout your body, explains Dr Vijay Murthy, functional medicine doctor and co-founder of Murthy Health.
“Because it’s essential for the oxygenation of your tissues, it impacts physical and mental performance, as well as immunity and other core bodily functions,” explains Rhian Stephenson, nutritionist and founder of supplement company Artah. It is also, she points out, involved in myriad other biological processes from neurotransmitter production – making it vital for brain function – to the health of our hair, skin and nails.
Prolonged deficiency can lead to anaemia (when your body does not produce enough red blood cells), but it can also take its toll on your heart, forcing it to work overtime to meet your body’s demands for oxygen. So what are the key signs and symptoms that your own levels are low?
1. Fatigue and weakness
“If you are constantly tired, no matter how much sleep you get, low iron could be the culprit,” says Murthy. Without enough iron, he explains, your muscles and tissues don’t get the oxygen they need, leaving you feeling drained.
2. Pale skin and pale inner eyelids
If you think you look like you might need a holiday then that may be true, but you might also want to get your iron levels checked. “Haemoglobin gives blood its red colour, so when there’s a shortage, skin and even the inner eyelids can lose their usual tone,” says Murthy. In fact, he explains, doctors use something known as the “pale eyelid test” as a quick and effective way to spot anaemia. Pull your lower eyelid down while looking in a mirror. The inside should be red. A pale or even yellow shade suggests you may have iron deficiency.
3. Shortness of breath
If climbing a few stairs suddenly feels like running a marathon, low iron might be to blame. “Haemoglobin helps carry oxygen, and when there’s less of it, your body ramps up breathing to get enough oxygen to your tissues,” says Murthy. “Roughly 60 per cent of people with iron deficiency report feeling out of breath, and the good news is that many see improvements within just six weeks of taking iron supplements.”
4. Heart palpitations
A racing or irregular heartbeat might be your heart’s way of compensating for low oxygen levels. “When iron is low, the heart works harder to pump blood, which can lead to palpitations,” explains Murthy. In fact, research suggests that iron deficiency increases the risk of cardiovascular issues by 41 per cent.
5. Headaches and dizziness
The brain needs a steady supply of oxygen, says Murthy, so when iron is low, it can trigger headaches or make you feel lightheaded. Last year, a study published in the International Headache Society’s journal found a “significant association” between iron deficiency and chronic daily headaches.
6. Brittle or spoon-shaped nails
If you’ve noticed your nails looking brittle or starting to curve outwards like little spoons, it might be something to look into. Low iron affects keratin production which, in severe cases, can lead to fragile, spoon-shaped nails, explains Murthy.
7. Cold hands and feet
Low iron can cause poor circulation, explains Murthy, often leading to cold hands and feet as blood-flow prioritises vital organs. Hands and feet aside, many sufferers report feeling generally chillier than those with normal iron levels, especially in winter.
8. Restless legs syndrome (RLS)
If you’ve ever felt a strange, uncomfortable crawling sensation in your legs, especially at night, low iron could be behind it, says Murthy. A systematic review published in 2016 found a significant association between the condition and iron deficiency.
9. Cravings for non-food substances (also known as pica)
“Believe it or not, low iron can sometimes cause odd cravings for non-food items like ice, clay or even dirt – a condition known as pica,” says Murthy. “While the exact reason remains unclear, some researchers think it might be the body’s way of searching for missing nutrients.” Ice craving (or pagophagia) is the most common form.
10. Sore or swollen tongue and mouth sores
A sore or swollen tongue, or cracks at the corner of your mouth, can also be a red flag, says Murthy. “Iron is essential for healthy tissues, and a shortage can lead to glossitis (swollen tongue) and angular cheilitis (cracks at the mouth corners).” This symptom is particularly common in those who have been deficient for quite some time, he says.
I’ve got the symptoms. So what next?
If you are concerned about your iron, ask your GP to give you a simple blood test so they can evaluate your levels, says Dr Laura Mooney, research and development scientist at Randox Health. “Doctors assess your iron status by measuring ferritin and transferrin saturation,” she explains.
Your body uses these proteins to store and transport iron around the body. A drop in iron levels will be accompanied by a drop in ferritin and transferrin saturation, so “lower than normal levels of these markers helps to confirm diagnosis of iron deficiency”.
A ferritin level of less than 15mcg per litre commonly confirms iron deficiency, and a transferrin saturation level of less than 16 per cent usually
My test revealed low iron. What now?
Supplements
Iron isn’t produced by our bodies, so we have to ingest it. However, you really shouldn’t take supplements without having a test first, suggests Stephenson: “Iron isn’t a supplement to be casual about. Unlike other vitamins and minerals, we aren’t able to excrete excess iron.” In fact, iron overload, or haemochromatosis, can damage your liver, heart and pancreas and lead to diabetes.
If you do need a supplement, then do choose carefully, she advises: “Iron is notorious for unpleasant side effects like constipation, cramping, and bloating. Ferrous fumarate and ferrous sulfate are more likely to cause unwanted side effects, whereas iron bisglycinate is the most gentle.” Ideally, she recommends looking for a brand that pairs iron bisglycinate with vitamin C since the latter can help your body to absorb iron. On the other hand, taking iron with caffeine, dairy or calcium-rich foods can slow absorption, Stephenson warns. So best to wait a couple of hours.
Food
“There are two types of dietary iron – heme iron and non-heme iron,” explains Stephenson. “Heme iron is found in animal-based foods, like meat, poultry and fish, and non-heme iron is found in plant-based foods; certain grains, nuts, leafy greens and legumes.”
The best sources of heme iron
Game meats are great sources of iron, with venison coming in at around 5.5mg per 100g, says Stephenson. Steak will have about 2.5-5g per 100g, depending on the cut. The fattier the cut, the less iron it has. Leaner cuts of lambs have around 2mg of iron per 100g. Shellfish like oysters, muscles and clams are also high in iron, with over 6mg per 100g serving.
The best sources of non-heme iron
Tofu and legumes are the best, says Stephenson. Firm tofu has about 3g per 100g. The same weight of cooked lentils boasts around 3.25g, while 100g of spinach contains about 2.4g. Bear in mind, however, that non-heme iron is not absorbed as well by the body. “You can increase absorption by consuming them with foods rich in vitamin C,” she advises.
