Understanding Iron Deficiency
What is Iron Deficiency — and Why Does it Matter?
Iron is one of the most essential minerals in the human body. It plays a central role in producing haemoglobin — the protein inside red blood cells that carries oxygen from your lungs to every tissue and organ. When your body does not have enough iron, haemoglobin production falls, oxygen delivery suffers, and you feel it in almost every aspect of daily life.
Iron deficiency is the most common nutritional deficiency in the world, and it is remarkably prevalent among people living in busy urban areas like Kingston upon Thames. Despite this, many people go undiagnosed for months or even years — either because they attribute their symptoms to stress, overwork, or simply "getting older."
Symptoms of Iron Deficiency
Persistent fatigue
Exhaustion that does not improve with rest — the most universal symptom of low iron.
Brain fog and poor concentration
Difficulty focusing, forgetfulness, and mental sluggishness — often mistaken for anxiety or burnout.
Breathlessness on exertion
Feeling short of breath during activities that previously felt manageable.
Hair loss and brittle nails
Noticeable thinning or shedding of hair, and nails that break or split easily.
Palpitations
The heart working harder to compensate for reduced oxygen-carrying capacity.
Cold hands and feet
Poor circulation resulting from reduced red blood cell function.
Who is Most at Risk?
Iron deficiency does not discriminate, but certain groups are significantly more vulnerable:
- Women with heavy periods (menorrhagia) — regular monthly blood loss depletes iron stores over time, often faster than the body can replenish them through diet alone.
- Vegans and vegetarians — plant-based iron (non-haem iron) is absorbed far less efficiently than iron from animal sources. Without careful dietary management, deficiency is common.
- Endurance athletes and active individuals — high physical demands increase iron requirements. Foot strike haemolysis in runners and intense sweating both accelerate iron loss.
- Post-surgical or post-partum patients — blood loss during surgery or childbirth can cause rapid and significant iron depletion.
- People with IBD, Crohn's disease, or coeliac disease — inflammation and gut damage impair the body's ability to absorb iron from food.
Iron Deficiency vs Iron Deficiency Anaemia
These two terms are often used interchangeably, but there is an important distinction. Iron deficiency refers to depleted iron stores (low ferritin) even if haemoglobin remains within the normal range. You can experience significant symptoms at this stage. Iron deficiency anaemia is the more advanced state where haemoglobin has also fallen below normal levels. Both conditions can benefit from IV iron therapy — your doctor will assess your blood results to determine the most appropriate approach.
Why Oral Iron Tablets Often Fall Short
Iron tablets are frequently the first treatment tried — and for some people, they work well. But many patients find them difficult to tolerate. Nausea, constipation, stomach cramps, and dark stools are common side effects that lead people to stop taking them. Even when tolerated, oral iron has limited bioavailability: only a fraction of what you swallow is actually absorbed by the body, and that absorption can be further reduced by gut conditions, other medications, or simply having your levels too low to begin with. For these patients, intravenous iron is not a last resort — it is simply the more effective route.
