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Vitamin B12 Deficiency

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Do you get enough Vitamin B12?

The impact of a Vitamin B12 deficiency on health is significant. B12 deficiency is one of the most common causes of anaemia. We all know that vitamins are important- but we don’t always know which ones and why. Vitamin B12, though less talked about than Vitamin C or D, is one of the most important.

Vitamin B12 is one of essential B vitamins for good energy metabolism at the cellular level. Vitamin B12 is necessary for the formation of red blood cells and plays a key role in the proper functioning of the nervous system. Vitamin B12 is a coenzyme needed for the production of red blood cells- the life-sustaining oxygen-carrying part of blood- so it easy to see how a lack of it could adversely affect health. A lack of vitamin B12 presents with fatigue, weakness, weight loss and, in more severe cases, with reduced cognition and numbness of the extremities.

Daily requirement

However, we are lucky that our daily requirement of this key vitamin is actually quite small. We need only 3-5 micrograms (note: 1000 micrograms equals one milligram) a day and the liver is good at storing around 2-5 milligrams in reserve. This means that it can take years for vitamin B12 deficiency to finally manifest.

Vitamin B12 can be found naturally in animal products such as milk, meat, eggs and fish. This explains why Vitamin B12 deficiency is a common problem among people who follow a vegan or vegetarian diet. It has also been linked to extreme weight loss, intestinal diseases, medicine use and excessive alcohol consumption. Vitamin B12 deficiency can cause all sorts of health issues, including:

  1. Fatigue
  2. Tingling sensation in the fingers or burning sensation in the hands, feet, arms or legs
  3. Memory and concentration problems
  4. Difficulty with coordination
  5. Muscle weakness in the legs
  6. Menstrual problems
  7. Infertility
  8. Nervousness, depression

Who is at risk of being vitamin B12 deficient?

Interestingly, the main cause worldwide is actually a lack of intake in the first place through the diet. Key vitamin B12 containing foods are meat, eggs and dairy products, so those whose diets tend to avoid these foods such as vegans are most at risk.

Additional Causes

To understand the other causes we need to remember that the body takes up Vitamin B12 from food by binding to a special substance produced in the stomach wall called Intrinsic Factor that makes it absorbable in the small intestine next door. So any process that affects the stomach and small intestine walls can affect the vitamin B12 levels.


Amnesia is a loss of ability to memorise information and or to recall information stored in memory. What we call memory, the ability to recollect our life´s experiences is a very complex process within the brain. Researchers are only beginning to understand what exactly happens when we commit something to memory or when we try to remember it.

Not all memories are permanent, so merely being a little forgetful is not the same as having amnesia. Amnesia is a large-scale loss of memories that otherwise would be unlikely to be forgotten, such as important life experiences and people, or things you have just been taught or told. Amnesia is often the symptom of a degenerative brain disease, such as Alzheimer´s disease, or may result from a traumatic injury to the brain. There has been much debate over whether the brain blocks particularly traumatic memories.


The biggest of these is an autoimmune condition called Pernicious Anaemia where the body doesn’t make this Intrinsic Factor. Other common reasons are having intestinal diseases like Coeliac Disease, Crohn’s Disease and Ulcerative Colitis. Those on long-term PPI’s (proton pump inhibitors like Omeprazole and Lansoprazole) may also be at risk for the same reason. Also, drinking alcohol can cause vitamin B12 deficiency as its effect on the stomach lining can mean less vitamin B12 is absorbed by food.

Treatment for B12

If you have or are worried about any of these causes of a lack of vitamin B12, the good news is that it is both easy to test for and easy to treat. A simple blood test through your doctor can diagnose it – and if you are found to be vitamin B12 deficient, it is easy to treat by a simple course of 6 vitamin B12 injections in the space of 3 weeks.

In some cases, depending on the cause, it may be necessary to have on-going injections – which are helpfully available just a few clicks away here on – once every 3 months to maintain vitamin B12 levels.

The B12 Calculator

In the UK you can always try using the B12 Calculator a to check if you have any B12 symptoms.

What does the Department of Health advise?

You should be able to get all the vitamin B12 you need by eating a varied and balanced diet. If you take vitamin B12 supplements, don’t take too much as this could be harmful.

Taking 2mg or less a day of vitamin B12 in supplements is unlikely to cause any harm.

Sources: NHS,

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