Iron is a mineral your body cannot function without. It is the core of haemoglobin, the protein in red blood cells that carries oxygen from your lungs to the rest of your body. When iron runs low, your body cannot make enough healthy red blood cells, and the result is iron deficiency, the most common nutritional deficiency in the world.
How to recognise low iron
Mild iron deficiency may cause no symptoms at all, but as it progresses it can develop into iron deficiency anaemia. Common signs include:
- Persistent tiredness and weakness, even after rest.
- Pale skin, especially inside the lower eyelids.
- Shortness of breath during ordinary activity.
- Dizziness, headaches, or a fast heartbeat.
- Cold hands and feet, brittle nails, or hair loss.
- Unusual cravings for non-food items like ice, a symptom called pica.
These symptoms overlap with many other conditions, which is why a blood test is the only reliable way to confirm iron deficiency rather than guessing.
Why iron levels drop
Iron deficiency has three broad causes: not getting enough, not absorbing enough, or losing too much. Understanding which applies matters for treatment.
- Insufficient intake: Diets low in iron-rich foods, including some vegetarian and vegan diets that are not well planned.
- Increased need: Pregnancy, infancy, and rapid growth in childhood raise demand.
- Blood loss: Heavy menstrual periods are a very common cause, as is slow gastrointestinal bleeding from ulcers or other conditions.
- Poor absorption: Conditions like coeliac disease or surgery affecting the gut can reduce how much iron the body takes in.
Food sources of iron
There are two kinds of dietary iron. Heme iron, from animal foods, is absorbed more easily than non-heme iron from plants. Good sources include:
- Red meat, poultry, and fish for heme iron.
- Beans, lentils, tofu, and chickpeas for plant-based iron.
- Dark leafy greens such as spinach.
- Fortified cereals and breads.
- Nuts, seeds, and dried fruit like apricots.
You can boost absorption of plant iron by pairing it with vitamin C, such as adding peppers, citrus, or tomatoes to a meal. Tea, coffee, and calcium-rich foods can reduce absorption, so it helps to separate them from iron-rich meals.
Why you should not just take supplements
It is tempting to buy iron pills the moment you feel tired, but this is a mistake. Fatigue has many causes, and taking iron you do not need can cause constipation and stomach upset, and in some people too much iron is harmful. Just as importantly, low iron can be a signal of an underlying problem, such as internal bleeding, that needs investigation. Always confirm deficiency with a blood test and take supplements under medical guidance, at the dose and duration your doctor recommends.
Treatment and recovery
Treatment depends on the cause. For dietary shortfalls, richer food choices and, if needed, oral iron supplements usually restore levels over a few months. Doctors often recheck blood tests to confirm improvement and to make sure the underlying cause has been addressed. In severe cases, or when supplements are not tolerated or absorbed, intravenous iron or other treatments may be used. With the right approach, most people recover fully and feel markedly better as their oxygen-carrying capacity returns to normal.
Getting the most from iron supplements
If your doctor prescribes iron, a few practices help it work while easing side effects. Taking it with a source of vitamin C, such as a glass of orange juice, can improve absorption, while tea, coffee, dairy, and calcium supplements taken at the same time can hinder it. If tablets upset your stomach, taking them with a little food or every other day may be gentler, and your doctor can advise on the best schedule. It also takes time: even after your blood counts recover, treatment often continues for a while to rebuild the body's iron stores fully.
This article is for general information only and is not professional medical advice. Talk to a doctor or qualified health professional about your own situation.