What is B12 deficiency?

So why is vitamin B12 so important?

Vitamin B12, along with Vitamin B9 (folate), helps your body produce red blood cells and is vital for keeping both your nervous system and immune system healthy. It is crucial for the construction of your DNA.

Where do I find vitamin B12?

This essential, complex vitamin is only found naturally in animal products (meat, poultry, fish, shellfish, dairy, and eggs), but starts as cobalt in soil. Vitamin B12 is also found in fortified vegetarian foods and in B12 supplements. However, please note that seaweed, spirulina and other plant foods contain B12 analogues (cobamides). This means that although these are very similar chemically, they are not recognised by the body and therefore cannot be used. These analogues can interfere with absorption of true vitamin B12 and disrupt B12 metabolism.

Why is vitamin B12 deficiency so damaging?

When the body does not have enough Vitamin B12 (a deficiency), the fatty tissue that surrounds your nerves (myelin) becomes damaged and can lead to brain damage, spinal cord damage, peripheral nerve damage and eye nerve damage. Vitamin B12 deficiency is a progressive neurological disorder and can result in symptoms ranging from severe anaemia requiring blood transfusions, to serious psychiatric conditions and potential misdiagnosis.

How is vitamin B12 absorbed?

Vitamin B12 deficiency is a particular problem for sufferers who cannot absorb B12 from food, even though their diet includes animal products or fortified vegetarian foods. Chemically, B12 must follow a complex pathway within the body for proper absorption. If your body has problems absorbing Vitamin B12 deficiency then follows. When this is the case, Vitamin B12 deficiency can only be effectively treated by injections of B12 (Hydroxocobalamin in the UK) and NOT oral supplementation.

There are many causes for vitamin B12 deficiency and pernicious anaemia is just one of them. If you’d like to look more in depth at this pathway, you can read further about the enterohepatic circulation here. 

Symptoms of vitamin B12 deficiency

The effects of Vitamin B12 deficiency can be far-reaching and long lasting which is why an early diagnosis and treatment are essential to stop permanent damage. It affects all body systems, both sexes and all ages, and symptoms can present in a number of surprising ways. Symptoms can also take years to develop. Symptoms of B12 deficiency can vary from mild to severely debilitating, and can be potentially life-threatening if left untreated and undiagnosed. You can read about the symptoms of Vitamin B12 deficiency here.

Body systems affected by B12 deficiency

• Neurological
• Haematological
• Immunological
• Vascular
• Gastrointestinal
• Musculoskeletal
• Genitourinary

A quick note on oral vitamin B12 supplements

Oral Vitamin B12 (cyanocobalamin) tablets will raise B12 serum levels but will not repair nerve damage in those who cannot absorb B12 from food. This Cochrane review found evidence on oral B12 verses B12 injections to be of low quality. Oral B12 should only be prescribed when the deficiency is caused by a proven dietary lack of B12. (Note: This is not to be confused with injectable cyanocobalamin which can and does heal nerves and is most commonly used in Canada and America – please see B12 treatment).

Common problems that patients face…

• Failure of healthcare professionals to recognise the neurological and psychiatric symptoms of B12 deficiency.
• The name ‘Pernicious anaemia’ confuses doctors – many patients NEVER present with anaemia/macrocytosis – this is very late stage. NICE and BNF Guidelines still categorise B12 deficiency under anaemia, this needs to change.
• Poor Diagnostic tests and reference ranges of B12 serum test range set so low missing severely deficient patients.
• The misconception that B12 deficiency is rare and only affects women over 60. In fact it is very common affects all body systems, all ages and both sexes.
• B12 deficiency can effect a baby in the womb, infants and children. There should be no delay in diagnosis and treatment as symptoms in children may not be completely reversible.
• Lack of understanding of the many causes of B12 deficiency and those at risk leading to misdiagnoses.
• Harmful maintenance dosage guidelines which restrict the vast majority of UK patients to just 4 B12 injections per year. There is no clinical evidence held by the Marketing Authorisation Holders or NICE and BNF for the restricted treatment regime for UK patients, this is based upon cost saving GP Audits and not care for the patient.
• The misconception that B12 injections are a placebo and that too much is toxic and yet it has been in safe use for over 60 years. B12 is a water soluble vitamin and any excess is excreted quickly via the bladder and bowel.
• Reliance on flawed B12 serum test results rather than symptoms can lead to permanent damage. The serum test may be recording as much as 80% inactive B12 in the body which is unusable.
• Incorrect treatment of neurological symptoms with oral B12 instead of vital B12 injections leads to irreversible damage.  
• Lack of understanding of the genetic, transport and methylation defects affecting B12 absorption and metabolisation.

If I've helped please consider buying me a coffee/leaving a virtual tip.
Doing this helps me to offer this free website to you and others around the world.
Thank you, I really do appreciate it.