Vitamin B12 plays an essential part in our health, and deficiencies can lead to severe issues. But what exactly does B12 do and how common are deficiencies? The answer may surprise you.

Known also as Cobalamin, Vitamin B12 is a nutrient that plays a crucial role in nerve function, , cognitive health, the production of red blood cells, and DNA synthesis. Low levels can lead to fatigue, brain fog, hormone imbalance, mental health problems, and physical disability.

Severe, longstanding deficiencies left untreated can lead to permanent brain and nerve damage, and even death. Sometimes this is caused by Pernicious Anemia, which is an Autoimmune B12 deficiency, where the body attacks the Intrinsic Factor in the gut necessary for proper absorption of B12.

B12 cannot be made by the body and so must come from the foods we eat, or supplementation. In addition, plants do not make B12, only animal products like meat, eggs and dairy which naturally contain B12. Most people are aware that people who eat vegetarian or vegan diets are at a higher risk of developing a B12 deficiency as this nutrient is often lacking in their diets. However virtually anyone can acquire a B12 deficiency, even if their diet contains foods plentiful with it.

Why is this? It is because there are many things that can prevent the body absorbing B12 from nutrients within food. For example, taking certain pharmaceutical drugs like antacids which suppress stomach acid but also block nutrient absorption within the stomach, in addition some anti-biotics, diabetic treatments, and anesthetics like nitrous oxide.

What are some of the symptoms of B12 deficiency?


  • Poor memory
  • Confusion
  • Dizziness
  • Vertigo
  • Fatigue
  • Difficulty walking
  • Anxiety
  • Paranoia
  • Sleep disturbance
  • Shortness of breath
  • Anemia
  • Heart palpitations
  • Neuropathy

These are just a few of the many potential symptoms of a B12 deficiency. B12 deficiency left untreated can also mimic other illnesses, including but not limited to Alzheimer’s, Parkinson’s, autism, MS, hypothyroidism, and heart disease. B12 deficiency can literally cause multi system failure at its most severe and is frequently inadequately tested for and missed as a potential cause for symptoms which mimic these diseases.

How can we test for B12 deficiency?

The most common test for B12 is the Serum B12 test which will essentially tell you how much B12 is within your blood stream. However, this test alone is not enough to establish or rule out a deficiency.

B12 serum test only tells you how much B12 is in your serum, not if the B12 is being absorbed and utilized by the body, which is far more important. For this we need an additional test, the MMA (Methylmalonic acid) test which looks for a of buildup of methylmalonic acid which is a strong indicator that your body is not absorbing B12 effectively.

The downside is that this test is expensive to run, and doctors may resist ordering it and instead rely only on serum B12. Testing Homocysteine levels can be another helpful indicator of B12 deficiency, as homocysteine levels will often be high in the bloodstream if there is B12 deficiency. To rule out Pernicious Anemia, an Intrinsic Factor antibody test needs to be performed.

Pernicious Anemia is the Autoimmune form of B12 deficiency and means the person will require B12 injections for the rest of their life because their body does not have enough Intrinsic Factor to sufficiently absorb and utilize the B12 that they are consuming through their diet or supplements.

A common approach is to supplement with B12 based on symptoms of a deficiency rather than testing, since B12 is nontoxic, and any excess is easily excreted in the urine, so it is difficult to have too much.

How to treat a B12 deficiency.

For mild cases and for people who are generally healthy without digestive issues and wish to prevent a deficiency, eating a diet with plenty of meat, dairy and eggs is ideal.

For those that wish to consume more, eating beef liver on a regular basis is ideal as this food is loaded with natural B12. For people with a severe B12 deficiency, or worse still, Pernicious Anemia, the best treatment is intramuscular B12 injections which can be obtained through a health professional or an online pharmacy.

B12 can also be purchased as a dietary supplement, usually in 1000-5000mcg pills taken sublingually, although if you have Pernicious Anemia even the sublingual supplement will not be enough to alleviate symptoms and injections are necessary.

To recap; B12 is an essential vitamin that we all need to survive, and deficiencies left untreated can cause severe physical and metal issues that are often mistaken for other diseases. Treatment is usually simple, but diagnosis can be a challenge.