It's worth noting too, that there are many people regularly consuming animal products that experience deficiency due to stress or poor gut health. For this reason, it's worthwhile knowing the signs and symptoms of a deficiency.
A vitamin B12 deficiency can express in the body in a number of different ways, with some symptoms a little more unusual than the more frequently reported tiredness and fatigue.
The reason that the symptoms are so varied is due to B12s multitude of roles in DNA, RNA, cellular metabolism, maturation of red blood cells, nervous system health and amino and fatty acid metabolism, meaning it can affect numerous systems within the body.
Whilst symptoms can be fairly mild, a continued insufficiency causes more obvious and indeed, more serious symptoms, with a prolonged B12 deficiency having the potential to cause irreversible damage in the body.
What to look out for
The list below is not extensive and there are many many more reported symptoms of a B12 deficiency, but here are 6 of the more obvious and common symptoms associated with a lack of this vitamin.
1. Pale skin
People with a B12 deficiency often look pale or have a slight yellow tinge to the skin and whites of the eyes, a condition known as jaundice. This happens when there is insufficient B12 to produce enough red blood cells. It’s the circulation of these underneath your skin that gives it its colour.
2. Weakness and fatigue
A very common symptom of vitamin B12 deficiency; as above, it occurs because your body has insufficient B12 to make red blood cells, which in turn transport oxygen (and nutrients) throughout your body. Without sufficient oxygen levels throughout our body we begin to feel fatigued and weakness in our muscles.
Often felt in the fingers and feet, tingling, prickling and numbness can in fact be felt in many parts of the body, including the tongue. This is one of the more serious side effects of a long-term B12 deficiency and if left untreated can cause irreversible nerve damage.
Vitamin B12 is an important contributor to the metabolic pathway that produces the fatty substance myelin, which surrounds your nerves as a form of protection and insulation. Without B12, myelin is produced differently meaning your nervous system isn’t able to function properly. This can occur over time and begin very mildly so it’s one to look out for.
4. Glossitis and Mouth Ulcers
Glossitis is a term used to describe an inflamed tongue. Your tongue changes colour and shape, and it can be swollen, red and painful. The inflammation can also make your tongue look smooth, as the taste buds are stretched out and seemingly disappear. Studies have shown that a swollen and inflamed tongue that has long straight lesions (cracks) on it could be an early sign of vitamin B12 deficiency.
In addition to this, mouth ulcers can become a common occurance in a B12 deficiency as well as Angular cheilitis; dry cracked, sores at the corners of the mouth, sometimes extending along the edge of the lip.
Anemia caused by a B12 deficiency, can cause a feeling of shortness of breath and dizziness, especially when you exert yourself.
This is due to a lack of red blood cells the body needs in order to get enough oxygen to your cells as well as the low blood pressure also caused by this deficiency. However, these symptoms can have many causes, so if you notice that you are unusually breathless, you should speak with your GP to investigate the cause.
6. Impaired Vision
One symptom of vitamin B12 deficiency is blured or disturbed vision. This can occur when an untreated B12 deficiency results in nervous system damage to the optic nerve that leads to your eyes. The damage can disrupt the nervous signal that travels from your eyes to your brain, affecting your vision. This condition is known as optic neuropathy. Whilst it can be alarming, it is often reversible with B12 supplementation.
Deficiency can show up in many ways
The above list is undoubtedly the more common of the deficiency symptoms, but read on for another 5 symptoms that you may not ordinarily associate with a B12 deficiency, but are worth looking out for.
1. Anxiety and Irritability
The role of B12 in the formation of myelin (the protective sheath around synapses which aids the conduction of nerve impulses) and in the health of the nervous system and normal function of the brain, means that an insufficiency of this vitamin can show up as anxiety and irritability.
Whilst these can be mild in the beginning, if left untreated can become very serious with reported episodes of perceptual disturbances.
2. Premature greying and hair loss not associated with aging
It may not be the first symptom you’d associate with a B12 deficiency but due to its role in activating melanocytes cells, which are responsible for hair pigmentation, prematurely greying hair can be a sign of an insufficiency.
B12 also plays a crucial role in maturation of red blood cells which carry oxygen and nutrients around our bodies. Hair growth is not essential to the survival of the human body, so the body will favour supporting the vital organs and we can see a reduction in hair growth and therefore, hair loss when the hair comes to the end of its life cycle.
3. Unusual metallic taste in mouth
Whilst this can have other causes, B12 deficiency (as well as zinc and vitamin D deficiencies) can cause this strange taste in the mouth.
4. Eye twitch
Whilst this can be caused by stress or a magnesium deficiency, there is a correlation between a B12 deficiency and eye twitches. It can occur on the eyelid or just below the eye and usually only occurs in one eye at a time. This is not usually painful, just annoying.
5. Constipation
A little bit of a chicken and egg situation here as the link between low B12 levels and constipation is linked by low Hydrochloric acid (stomach acid). Stomach acid is essential for the absorption of B12 from food and with low levels (caused by a number of things such as aging, stress and medication) comes a decreased ability to properly digest and assimilate our food. Of course B12 also plays a role in metabolism and therefore the slower the metabolism, the slower the gut motility.
Is a B12 supplement the ‘Cure’?
When choosing a Vitamin B12 supplement, it’s important to keep in mind that they’re not all created equal. Cyanocobalamin is a synthetic form of B12 that has been bound to a cyanide molecule (which of course then needs to be removed by the body’s detoxification pathways), while methylcobalamin and adenosylcobalamin are both forms of B12 that are active. This means that your body is not required to convert the vitamin in anyway before it can utilise it. Both of these forms play varying roles in supporting the body’s DNA and RNA production, nervous system health and energy production are the most bioavailable options available.When treating a B12 deficiency, while the underlying cause is being investigated, use of an activated form of the vitamin is recommended, and preferentially effective at improving levels.
Bioactive B12 is one of the purest, most bioavailable B12 supplement options available. Offering both active forms of B12, this easy to absorb liquid sublingually delivers both Methylcobalamin and Adenosylcobalamin straight to your bloodstream for improved and faster results. The only other ingredient? Reverse osmosis water.
If you'd like to find out who is most at risk of a B12 deficiency read my article B12 SUPPLEMENTS: WHY THEY'RE NOT JUST FOR VEGANS but if you do experience any number of the 11 symptoms above, a test with your GP to check your levels may be beneficial. 
Rachel Aceso
Nutritionist and CEO
Nature Provides
