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What is B12 deficiency?

Vitamin B12 deficiency is progressive neurological disorder, it affects all body systems and all ages. There is a downloadable poster which demonstrates some of the conditions which can occur with low B12 or indeed may be misdiagnosed in place of B12 deficiency. 

We have also developed an app to help determine your risk of B12 deficiency.


As you will see this deficiency causes a huge array of sometimes surprising symptoms which may take years to develop. This severely debilitating, potentially life threatening deficiency can be easily diagnosed, and so easily and inexpensively treated IF our health professionals update their knowledge.

Correctly diagnosing this deficiency would save billions in medication and care around the world.

If you think you are B12 deficient please head straight to the What to do next page. If you are deficient but are not being treated properly please use the 'writing to your doctor' page.

You can view a 90 minute broadcast on B12 deficiency with me, from the Academy of Physical Medicine here. There is a small charge. 

Vitamin B12 (cobalamin) is one of the family of 13 vitamins and is essential to life and health. B12 along with folate (Vitamin B9) is essential for the production of red blood cells and aids in the maintenance of a healthy nervous system and immune system. B12 deficiency damages the fatty tissue - myelin - which surrounds and protects nerve fibres, it damages the brain, spinal cord, peripheral nerves, and nerves of the eye.

It is a crucial element in the construction of DNA. It can result in symptoms ranging from severe anaemia requiring blood transfusions, to serious and permanent nerve damage and psychiatric conditions.

B12 is found in animal products (meat, poultry, fish, shellfish, dairy, and eggs), but starts as cobalt in soil. It is also found in fortified vegetarian foods and in B12 supplements. However, please note seaweed, spirulina and other plant foods contain B12 analogues, these are NOT accessible to the body. 

B12 must follow a complex pathway of several steps for proper absorption. A problem in any part of this pathway can cause malabsorption and subsequent deficiency. Read about The Enterohepatic Circulation here.

This deficiency presents a particular difficulty for sufferers who cannot absorb B12 from food even though their diet includes animal products or fortified vegetarian foods. It can only be effectively treated in the UK by a prescribed injection of B12 (Hydroxocobalamin) and NOT oral supplementation.

Oral cyanocobalamin tablets will raise B12 serum levels but will not repair nerve damage. These should only be prescribed when the deficiency is caused by a proven dietary lack of B12. (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). We are entirely reliant upon our doctors knowledge of this condition and as you might find, this can be tragically lacking. 

Systems affected by B12 deficiency

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