Vitamin B12 Deficiency, Nerve Pain & Fatigue – What you need to know.

Vitamin B12, or cobalamin is one of eight essential B Vitamin nutrients required for amino acid metabolism, energy production, nervous system function and mood (to name a few). It is the most chemically complex of all the vitamins. Vitamin B12 is not considered by GPs as a ‘red book’ routine test in Australia and therefore, a deficiency can fly under the radar in many individuals.

How does a deficiency cause fatigue and nerve pain?

Vitamin B12 is required for cellular energy production and metabolism, and is an important part of the Krebs Cycle. This promotes the production of adenosine triphosphate (ATP), which is the energy source for your brain and cells throughout your whole body.
Without B12, hello fatigue!

Vitamin B12 deficiency may also cause demyelination of nerves (loss of the nerve insulation) in the peripheral and central nervous systems. It is associated with large fibre (type A) neuropathy, and signs of a deficiency are generally nerve pain, pins and needles and tingling in both the hands and feet.

Top 5 signs that you might have B12 deficiency:

  • Fatigue
  • Nerve pain
  • Tingling in hands and feet
  • Mood changes
  • Poor sleep

How can we become deficient?

To understand how deficiency occurs, we must first understand how Vitamin B12 is absorbed. Vitamin B12 absorption happens in the gut. This is generally a two-step process to turn B12 into a form for the body to store it via in the liver.

Firstly, your digestive juices (hydrochloric acid) separate Vitamin B12 from the protein it’s attached to. After that, Vitamin B12 is free to attach to another protein (salivary R) in the small intestine using both pancreatic enzymes and the intrinsic factor, to help the body absorb it.

Anything that interrupts these absorption steps, which could be a disease or condition of the gastrointestinal tract or a medication that interferes with digestion, may potentially reduce your body’s absorption of Vitamin B12.

What are the most common things that reduce B12 absorption?

Long-term use of anti-reflux medications called protein pump inhibitors (“PPIs”)


Anti-reflux medications are the top 10 most over-prescribed medications in the world. Generally prescribed or available off-shelf for acid reflux conditions and symptoms of heartburn and indigestion. This medication effectively blocks gastric acid secretion (hydrochloric acid) in the stomach, which is required for the first stage of Vitamin B12 absorption. This medication is only recommended short-term however, for many people they continue to take it for a lifetime.


A vegan or vegetarian diet

Vitamin B12 is found in mostly animal-based foods. That includes animal meats, eggs, seafood and dairy products. Vitamin B12 from plant-based sources is considered negligible, and many foods are fortified in this case such as plant-based milks and cereals. Limiting animal-based foods can lead to a deficiency and supplementation is required on-going.

Gastrointestinal conditions

Many gastrointestinal conditions and diseases that impair absorption of Vitamin B12 include:

    • Coeliac disease
    • Ulcerative Colitis
    • Irritable bowel syndrome
    • SIBO (Small intestinal bacterial overgrowth)
    • Bariatric surgery
    • Elderly people

If you are feeling very tired, experiencing pins and needles, changes in mood, and nerve pain, it may be a sign of Vitamin B12 deficiency.

You can get your levels checked by working with a combination of our Naturopath Melissa McDonald and your GP. Begin by booking a Naturopathic consultation with Melissa, who will focus on not only boosting your nutrient levels, but also ensuring proper nutrient absorption.

To learn more about Naturopath Melissa McDonald and Naturopathy, visit our website by clicking here. You can also book your appointment online by clicking here.