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#11 Vitamin B12 Deficiency and its’ Tie to PN

In the past few years the supplement and vitamin industry has been growing exponentially and it is common to hear about different types of vitamins and how they can benefit our body- but, what we don’t hear about as often is vitamin deficiencies. Certain vitamins, or lack thereof, have been clearly linked to various conditions, including peripheral neuropathy. Vitamin B12 is one of the vitamins which can provoke peripheral if a deficiency occurs.

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What is Vitamin B12?

Vitamin B12, also known as Cobalamin, is an essential nutrient. This means that it is required for normal body functioning. Our bodies cannot synthesize Vitamin B12, and therefore, we need to obtain it in our diet. Vitamin B12 is broken up in the stomach by Hydrochloric Acid and then is absorbed into the stomach by binding to a protein called Intrinsic Factor. Vitamin B12 is then stored in the liver. We need Vitamin B12 for functions such as making red blood cells, DNA, RNA and myelin which covers nerve fibres.  

Where Does Vitamin B12 Come From?

Vitamin B12 is found naturally in animal products and can also be added to fortified foods, such as cereals. We can obtain sufficient B12 by either eating foods that contain Vitamin B12, or consuming supplements with Vitamin B12. The most commonly consumed sources of Vitamin B12 are fish, red meat, poultry, milk, eggs and dairy products. For those individuals who do not consume meat or dairy, Vitamin B12 is often consumed through nutritional yeasts, cereals or non-dairy milks fortified with B12. Vitamin B12 is also found in supplement form in many multivitamins and in B complex vitamins.

Vitamin B12 Graphic
B12 is common in fish, red meat and other foods
Image Source: https://www.goodfreephotos.com

What Causes a Vitamin B12 Deficiency?

When we are lacking a vitamin in our diet this is called a vitamin deficiency. A Vitamin B12 deficiency is the product of one of two things, either: a) Not consuming enough Vitamin B12 in the diet or, b) the body not absorbing Vitamin B12 for whatever reason and thereby, even if Vitamin B12 is consumed, it does not stay within the body.

As the first point alludes to, a diet which lacks animal products i.e. Vitamin B12, and does not adequately supplement Vitamin B12 can result in a deficiency. This is very rare though and generally is only seen in strict vegans.

Malabsorption (improper absorption) of vitamins means that although a vitamin or other substance is being consumed, it is not being absorbed into the body once it is ingested, and so instead it is excreted. This process denies our bodies from the benefit that we would obtain from this nutrient. In the case of Vitamin B12, it is absorbed into the body in a two-step process as outlined earlier. First the vitamin is broken down in the stomach- breaking the vitamin down allows it to be absorbed easier, and then it is absorbed into the lining of the stomach by attaching to a protein called Intrinsic Factor. If anything hinders this process, either preventing the initial breakdown of the vitamin or the attachment of the vitamin to Intrinsic Factor, the vitamin will not be absorbed. If we do not absorb the vitamin, it is as though we never had it because the vitamin is only useful when properly absorbed into the body.

Pernicious anemia is a condition where an individual cannot make the Intrinsic Factor protein and thus, individuals cannot absorb Vitamin B12. Malabsorption can have many causes though, including gastric surgeries, alcoholism, autoimmune disease, Crohn’s Disease and more.

What Happens When We Have a Vitamin B12 Deficiency?

Vitamin B12 deficiency can lead to a number of serious conditions, one of them of course being peripheral neuropathy. This occurs because Vitamin B12 plays a very important role in the synthesis of the myelin sheath. The myelin sheath is a protective covering that surrounds your nerves, protecting them from damage as well as providing quicker nerve transmission. Without Vitamin B12, the myelin sheath becomes damaged or weakened which impairs the proper functioning of our nerves.

Anemia is often one of the first signs of Vitamin B12 deficiency, however, this is not always the case. Vitamin B12 deficiency can progress into degeneration within the spinal cord which can cause loss of sensation in both the hands and feet simultaneously. This simultaneous loss of sensation is often an indicator that this peripheral neuropathy is caused by a Vitamin B12 deficiency.

Vitamin B12
Anemia, a shortage of red blood cells, can be a sign of B12 deficiency

Treating Peripheral Neuropathy Caused by a Vitamin B12

Early diagnosis and treatment of a Vitamin B12 deficiency is very important as it can help to restore damaged nerves. Having said that, there is a point at which nerves are damaged beyond repair and then the focus of treatment is instead to prevent any further damage from the deficiency.

The treatment options will depend on a few factors but will involve increasing Vitamin B12 in the body. It will be considered whether the deficiency is due to a lack of Vitamin B12 consumption, or an absorption issue. Oral supplementation of Vitamin B12 is often recommended and Vitamin B12 injections are sometimes necessary as well. In addition to this, it is frequently recommended to increase Vitamin B12 consumption in the diet by eating foods high in Vitamin B12 such as red meat, poultry and eggs, dairy products and fish.

Vitamin B, and specifically B12 helps many people with the ‘electric shock’ nerve pains.  Many people with neuromuscular disorders have found some relief by adding this to their daily routine.  Choose a good quality brand as not all are created equal.

Vitamin B Complex supplements include more than just B12, they include a spectrum of B vitamins.  It is important to be careful as too much Vitamin B6 can be neuro toxic and causing other problems.  Ensure you are getting only the daily recommend amount of B6 (1.0 to 1.7 mg depending on age)*.

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Food for thought...


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  • Ekabe, C., Kehbila, J., Abanda, M., Kadia, B., Sama, C. and Monekosso, G., 2017. Vitamin B12 deficiency neuropathy; a rare diagnosis in young adults: a case report. BMC Research Notes, 10(1).
  • Foundationforpn.org. 2020. Nutritional And Vitamin Deficiency Neuropathy | The Foundation For Peripheral Neuropathy. [online] Available at: <https://www.foundationforpn.org/what-is-peripheral-neuropathy/causes/vitamin-nutrition-deficiency/> [Accessed 22 April 2020].
  • McCombe, P. and McLeod, J., 1984. The peripheral neuropathy of vitamin B12 deficiency. Journal of the Neurological Sciences, 66(1), pp.117-126.
  • Ods.od.nih.gov. 2020. Office Of Dietary Supplements – Vitamin B12. [online] Available at: <https://ods.od.nih.gov/factsheets/VitaminB12-Consumer/> [Accessed 22 April 2020].
  • Peripheralneuropathycenter.uchicago.edu. 2020. Types Of Peripheral Neuropathy – Systemic / Metabolic – Nutritional / Vitamin Deficiency. [online] Available at: <http://peripheralneuropathycenter.uchicago.edu/learnaboutpn/typesofpn/systemic/nutrition.shtml> [Accessed 22 April 2020].
  • Staff, E.,Windebank A., 2014. Peripheral Neuropathy due to vitamin deficiency, toxins and medications. American Academy of Neurology, volume 5, pp1293-1306.
  • * https://ods.od.nih.gov/factsheets/VitaminB6-HealthProfessional/

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