Vitamin B12 – What you need to know

Vitamins are vital to the body’s many functions from helping to build muscles to helping to remove toxins from the body. Some vitamins may help to protect against illness whilst others help within the body’s energy cycle – of which B12 is one of them.

We can’t make vitamins and so eating or supplementing is the only way we can provide our body with these vital pieces of the nutritional jigsaw puzzle. Some vitamins may be stored within our body fat and are there for times of need, whilst others are not stored and need to be topped up daily.

B12 is one of those vitamins that needs topping up, although some is stored in the liver. A deficiency of B12 can deplete this liver store gradually to the point that we become deficient if we are not taking more in on a regular basis.

B12 is a vitamin that most vegans know about as it is almost exclusively found within animal products as it is formed in the gut of animals. Although found in some non-animal foods it is usually fortified and not absorbed as well. Non-animal sources of B12 can be found in fortified cereals, non-dairy milks such as almond or soya, yeast extract and nutritional yeast (which is a deactivated form of yeast in the form of flakes).
However, what a lot of people don’t realise is that it isn’t just vegans or even vegetarians who may need to get their vitamin B12 levels checked. B12 follows a complicated pathway and needs to be broken down by pepsin (an enzyme found in the stomach). In some people, especially those over 50, hydrochloric acid can be low in the stomach and thus pepsin is not produced as well as it should be. This affects the amount of B12 that can be absorbed – regardless of how much is actually eaten. It should be noted that antacids and proton-pump inhibitors can also reduce stomach acid, therefore those who take these may be lower in B12 than they think. Some gastric disorders such as Crohn’s Disease can also reduce absorption of B12.

Another important player in the B12 pathway is a protein called Intrinsic Factor. Some people have an inherited disorder where they don’t produce Intrinsic Factor. Therefore, if someone in your family has been diagnosed with a B12 deficiency, it may be worth while to get your own levels checked.

So, why should you be concerned about a B12 deficiency? Well, a B12 deficiency can cause mental disorders from anxiety to depression. It can present symptoms such as dizziness, tingling in extremities, falls, dementia (which is often put down to old age, but could be due to a B12 deficiency). A B12 deficiency can also mimic symptoms of Multiple Sclerosis, Chronic Fatigue, give rise to unexplained fertility problems, a failure to thrive in infants, memory loss, personality change and many, many more.

Most routine blood tests do not cover a B12 check and so you need to ask for it to be checked in addition. Also, higher levels of other B vitamins can mask a B12 deficiency which may be missed by your GP.

The lower level for B12 varies all over the world, but more surprisingly it even varies all over the UK. In some parts of the UK the lower acceptable level for B12 is 200pg/ml however, symptoms can be seen in people from 450pg/ml and below. There is some argument amongst experts that the lower level should even be raised to 550pg/ml and with levels to be nearer 1,000pg/ml in the elderly. Dr Joseph Chandy suggests a subtle B12 deficiency may be present with levels between 300-450pg/ml, an intermediate deficiency between 200-300pg/ml, and a severe deficiency below 200pg/ml
(reference –

The signs of deficiency are vast – as well as the ones previously mentioned, B12 deficiency could result in vision changes, incontinence, DVT, heart attacks, strokes, shortness of breath, gastrointestinal problems, weakness, premature grey hair, tinnitus, pour wound healing, indigestion and abdominal pain. It must be noted that if you have one or more of these it does not mean that you necessarily have a B12 deficiency, but if your GP has tested you for various things and you still feel that you are not getting answers, then it maybe worth getting your B12 levels checked. If you do think that you may be B12 deficient then it is important that you do not supplement with B vitamins before getting your levels tested as this can give you a false positive.

It is always a good idea to consult with a Nutritional Therapist if you feel that your diet may be lacking in any vitamins or minerals. Reference:
Pacholok, S.M. And Stuart, J.J. (2011). Could It Be B12? An Epidemic of Misdiagnoses. Published by Quill Driver Books.