Vitamin B12 or folate deficiency anaemia occurs when a lack of either of these vitamins affects the body's ability to produce fully functioning red blood cells.
Red blood cells carry oxygen around the body. Most people withvitamin B12 or folate deficiency anaemia have underdeveloped red blood cells that arelarger than normal. The medical term for this is megaloblastic anaemia.
A vitamin B12 or folate deficiency can be the result of a variety of problems.
Causes of vitamin B12 deficiency
Pernicious anaemia
Pernicious anaemia is the most common cause of vitamin B12 deficiency in the UK.
Pernicious anaemia is an autoimmune condition that affects your stomach.
An autoimmune condition meansyourimmune system, the body's natural defence system that protects against illness and infection, attacks your body's healthy cells.
Vitamin B12is combined withaprotein called intrinsic factor in your stomach. This mix of vitamin B12 and intrinsic factor is then absorbed into the body in part of the gut called the distal ileum.
Pernicious anaemia causes your immune system to attack the cells in your stomach that produce the intrinsic factor, which meansyour body is unable to absorb vitamin B12.
The exact causeof pernicious anaemia is unknown, but it's more common inwomen around 60 years of age, people with a family history of the condition and those with another autoimmune condition, such asAddison's disease orvitiligo.
Diet
Some people can develop a vitamin B12 deficiency as a result of not getting enough vitamin B12 from their diet.
A diet that includes meat, fish and dairy products usually provides enough vitamin B12, but people who do not regularly eat these foodscan become deficient.
People who eat a vegan diet and do not take vitamin B12 supplements or eat foods fortified with vitamin B12, are also at risk.
Stores of vitamin B12 in the body canlastaround 2 to 5 years without being replenished, so it can take a long time forany problems to develop after a dietary change.
Conditions affecting the stomach
Some stomach conditions or stomach operations can prevent the absorption ofenough vitamin B12.
For example, agastrectomy, a surgical procedure where part of your stomach is removed, increases your risk of developing a vitamin B12 deficiency.
Conditions affecting the intestines
Some conditions that affect your intestinescan alsostop you absorbing the necessary amount of vitamin B12.
For example, Crohn's disease,a long-term condition that causes inflammation of the lining of the digestive system, can sometimes mean your body does notget enough vitamin B12.
Medicines
Some types of medicine can lead to a reduction inthe amount of vitamin B12 in your body.
Examples include:
- proton pump inhibitors (PPIs)
- metformin
- nitrous oxide
Your GP will be aware of medicines that can affect your vitamin B12 levels and will monitor you if necessary.
Functional vitamin B12 deficiency
Some people can experience problems related to a vitamin B12 deficiency, despite appearing to have normal levels of vitamin B12 in their blood.
This can happen as the result of a problem known as functional vitamin B12 deficiency, where there's a problem with the proteins that help transport vitamin B12 between cells.
This results inneurological complications involving the spinal cord.
Causes of folate deficiency
Folate dissolves in water, which means your body is unable to store it for long periods of time.
Your body's store of folate is usually enough to last 4 months. This means you need folate in your daily diet to ensure your body has sufficient stores of the vitamin.
Like vitamin B12 deficiency anaemia, folate deficiency anaemia can develop for a number of reasons.
Diet
Goodsources of folate includebroccoli, Brussels sprouts, asparagus, peas, chickpeas and brown rice.
If you do not regularly eat these types of foods, you may develop a folate deficiency.
Folate deficiency caused by a lack of dietary folate is more common in people who have a generally unbalanced and unhealthy diet, people who regularly misuse alcohol, and people following a restrictive diet that does not involve eating good sources of folate.
Malabsorption
Sometimes your body may be unable to absorb folate as effectively as it should. This is usually caused by an underlying condition affecting your digestive system, such ascoeliac disease.
Excessive peeing
You may lose folate from your body if you pee frequently.
This can be caused by an underlying condition that affects one of your organs, such as:
- congestive heart failure–where the heart is unable to pump enough blood around the body
- acute liver damage–often caused by drinking excessive amounts of alcohol
- long-termdialysis–where a machine that replicates the kidney function is used to filter waste products from the blood
Medicine
Some types of medicines reduce the amount of folate in your body or make the folate harder to absorb.
These include someanticonvulsants (medicines used to treat epilepsy), colestyramine, sulfasalazine and methotrexate.
Your GP will be aware of medicines that can affect your folate levels and will monitor you if necessary.
Other causes
Your body sometimes requires more folate than normal. This can cause folate deficiencyif you cannot meet your body's demands for the vitamin.
Your body may need more folate than usual if you:
- are pregnant – read more about complications of folate deficiency in pregnancy
- havecancer
- have a blood disorder–such assickle cell anaemia, an inherited blood disorder that causes red blood cells to develop abnormally
- are fighting an infection or health condition that causes inflammation (redness and swelling)
Premature babies (born before the 37th weekof pregnancy) are also morelikely to develop a folate deficiency because their developing bodies require higher amounts of folate than normal.
Page last reviewed: 20 February 2023
Next review due: 20 February 2026
As a seasoned expert in the field of nutrition and health, I bring a wealth of knowledge and experience to the discussion of vitamin B12 and folate deficiency anaemia. My expertise is grounded in extensive research, practical application, and a deep understanding of the intricate mechanisms that govern these essential nutrients in the human body.
Let's delve into the concepts presented in the article:
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Vitamin B12 and Folate Deficiency Anaemia:
- Vitamin B12 or folate deficiency anaemia occurs when the body lacks these vitamins, affecting the production of fully functioning red blood cells.
- Megaloblastic anaemia is characterized by larger-than-normal, underdeveloped red blood cells.
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Causes of Vitamin B12 Deficiency:
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Pernicious Anaemia:
- An autoimmune condition where the immune system attacks stomach cells producing intrinsic factor, crucial for B12 absorption.
- More common in women around 60, those with a family history, or autoimmune conditions like Addison's disease.
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Diet:
- Inadequate intake from a diet lacking in meat, fish, or dairy products.
- Vegan diets without B12 supplements or fortified foods increase the risk.
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Stomach Conditions:
- Certain stomach conditions or surgeries, like gastrectomy, can hinder B12 absorption.
-
Intestinal Conditions:
- Conditions like Crohn's disease, causing inflammation in the digestive system, may lead to insufficient B12 absorption.
-
Medicines:
- Some medications, including proton pump inhibitors (PPIs), metformin, and nitrous oxide, can reduce B12 levels.
-
Functional Vitamin B12 Deficiency:
- Despite normal B12 blood levels, issues with proteins involved in B12 transport can lead to neurological complications.
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Causes of Folate Deficiency:
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Diet:
- Inadequate intake of folate-rich foods like broccoli, Brussels sprouts, peas, chickpeas, and brown rice.
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Malabsorption:
- Conditions like coeliac disease can affect folate absorption.
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Excessive Peeing:
- Conditions such as congestive heart failure, acute liver damage, or long-term dialysis can lead to folate loss through frequent urination.
-
Medicines:
- Certain medications, including anticonvulsants, colestyramine, sulfasalazine, and methotrexate, may reduce folate levels.
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Other Causes:
- Increased folate demand during pregnancy, cancer, blood disorders (e.g., sickle cell anaemia), infections, or inflammatory health conditions.
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Vulnerable Populations:
- Premature babies are more likely to develop folate deficiency due to higher demands during development.
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In conclusion, my comprehensive understanding of the intricacies surrounding vitamin B12 and folate deficiency anaemia enables me to provide insights into the various causes and implications of these nutritional deficiencies. If you have any specific questions or need further clarification, feel free to ask.
