Iron Deficiency
Iron Deficiency
The National Institute for Health and Care Excellence (NICE) guideline on iron deficiency was last revised in August 2024. The guideline covers the management of iron deficiency anaemia, including its underlying causes and treatment with oral iron supplements
Iron deficiency, a condition where the body lacks sufficient iron, a mineral crucial for red blood cell production, enabling oxygen transport throughout the body. Iron deficiency can cause fatigue, weakness, and other health problems.
Iron deficiency anaemia often has multiple causes, including dietary insufficiency, poor absorption, blood loss, or increased iron demands. It’s a common complication of coeliac disease and can also occur alongside pernicious anaemia. Multiple factors may contribute to iron deficiency in an individual.
Common Symptoms
- Fatigue
- Shortness of breath
- Headache
- Pallor (paleness)
- Glossitis (sore tongue)
- Mouth sores
- Nail changes
(Note: Symptoms can vary and may be absent in some cases, some symptoms overlap with those of B12 deficiency)
Iron deficiency diagnosis
Serum Ferritin: This blood test primarily reflects iron stores.
NICE guidelines recommend a ferritin level below 30 micrograms/litre (µg/L) as indicative of iron deficiency.
Important Considerations:
- Inflammation and infection can elevate ferritin levels, complicating interpretation.
- Ferritin levels may be less reliable during pregnancy.
- Based on Laboratory results, some GP practices are still using a lower ferritin threshold (15 µg/L) notwithstanding the NICE Guideline on Iron Deficiency. This comes from the World Health Organisation data where the ferritin threshold is 15 ug/L. If you are symptomaticou may need to ask for other blood tests including an iron panel test to check how your body is using iron or a blood film to look at the size and shape of the cells. (Iron deficiency makes the cells smaller microcytic anaemia)
- A low MCV (mean cell volume) would be indicative of iron deficiency when combined with low haemoglobin or low ferritin.
- GP surgeries may over-rely on haemoglobin levels, overlook other indicators and dismiss symptoms. We strongly recommend that you obtain copies of all your full blood test results from your GP and do not rely on numbers quoted to you over the phone or text.
Refer to the NHS guideline on iron deficiency diagnosis for further information: Investigations | Diagnosis | Anaemia – iron deficiency | CKS | NICE
The Impact of Vitamin B12 deficiency
- A vitamin B12 deficiency and an iron deficiency can co-exist. Interpreting blood results will become challenging if this is the case.
- Since there can be several reasons for iron deficiency it is important that the cause is investigated. The NICE Guideline on iron deficiency says that investigating the cause of iron deficiency is essential.
- In clinical practice, most cases of iron deficiency result from excessive blood loss, usually unnoticed bleeding which continues for a long time. In women of child-bearing age, heavy periods may be a cause. Chronic bleeding into the gastrointestinal tract is the other common cause of iron deficiency, and this can be detected by a stool test for blood. It may come from the stomach, especially in patients taking anti-inflammatory drugs or aspirin but it also commonly comes from lower down, due to colorectal cancers. Iron deficiency can also be the result of certain diets such as vegetarian/vegan.
- The other important cause is conditions in the stomach where there is damage to parietal cells for example Pernicious Anaemia along with coeliac disease and various other small bowel. Patients with Pernicious Anaemia commonly have low stomach acid or may be prescribed PPI’s which can lower stomach acid and low stomach acid can lead to iron deficiency.
- B12 deficiency is likely to impact the small bowel cells where iron is absorbed as well and PAS are conducting research into the prevalence of iron deficiency alongside pernicious anaemia and B12 deficiency.
- B12, iron (and folate) are all required for healthy production of red blood cells.
Iron Supplementation
Caution is advised
- Iron Overload: Excessive iron can damage organs like the liver, heart, and pancreas.
- Side Effects: Common side effects include constipation, nausea, diarrhoea, and stomach upset.
- Drug Interactions: Iron can interact with certain medications.
- Misdiagnosis: Unnecessary supplementation can mask underlying causes.
- Consult your doctor: Always discuss iron supplementation with your doctor to determine the appropriate dosage and monitor for potential issues.
- There is a range of iron supplements available. Dose, palatability, formulation and bioavailability all vary. Taking advice to ensure you take the right amount of iron in the right format for the right length of time, monitored by subsequent testing if necessary, is important. People often under dose on iron because they do not like the bowel side effects.
Follow updates on our research into iron deficiency and Pernicious Anaemia here: Pernicious Anaemia Research
Further information available here: Folic acid, iron and vitamin B6
Understanding the relationship between B12 and other vitamins and minerals webinar here: What you need to know about Pernicious Anaemia and Vitamin B12 Deficiency
Paper on Autoimmune Gastritis and Stomach Acid by Professor Lori Taylor et al. Creating a Framework for Treating Autoimmune Gastritis – The Case for Replacing Lost Acid