Our body uses and metabolizes different vitamins and minerals for multiple physiological processes. Vitamin B12, even though quite underrated, is one of the most crucial vitamins needed for energy production, DNA synthesis, and supporting the nervous system’s functions in the body.

The reports of Vitamin B12 deficiency are becoming more and more prevalent in countries like India, Mexico, Central, and South America, Africa, etc. The prevalence is also increasing in the United States.

People often villainize diets and lifestyle choices like being vegan or vegetarian as the primary reason behind Vitamin B12 deficiency, which isn’t the sole reason. In fact, the body’s efficiency in absorbing nutrients depletes drastically with age, leading to deficiency.

This article will look into some of the alarming symptoms of Vitamin B12 deficiency and what you can do to combat it. Also, you can book a Vitamin b12 test in Delhi to check if you might have any deficiencies.

What are the Causes of Vitamin B12 Deficiency?

The causes behind Vitamin B12 deficiency are often due to lifestyle, physiological and dietary complications. It can be a direct consequence of:

Dietary choices – Vitamin B12 is primarily found in animal products like eggs, milk, meat, etc. So, not including those in the diet will drastically hamper the availability of Vitamin B12 in the body, thereby leading to deficiency.

Pernicious anemia – this is an autoimmune disorder where the immune system attacks the intrinsic factor in the stomach, which is responsible for Vitamin B12 absorption in the body.

Gastric surgeries – excision of parts of the stomach or intestine producing the intrinsic factor might lead to malabsorption of Vitamin B12, leading to deficiencies.

Intestinal complications – people with Crohn’s disease or Celiac disease are at heightened risk of developing Vitamin B12 deficiency as opposed to someone with a healthy intestinal function.

Now that you know the causes let us move on to the symptoms.

What are the Symptoms of Vitamin B12 Deficiency?

Vitamin B12 deficiency is quite prominent in the body because it manifests as alarming symptoms. You only need to be vigilant and take notes of the symptoms you are experiencing instead of brushing them to the curbside.

Following are some of the major symptoms you should look out for:

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1. Experiencing Fatigue and Weakness

It could be more than work stress if you are chronically fatigued and feel tired and weak day after day. Vitamin B12 plays a crucial role in the body’s energy production, so when you are running low on that, chances are that your body won’t have enough energy to keep you going through the day.

Moreover, Vitamin B12 deficiency is associated with depleted red blood cell production, which prevents optimal oxygen supply throughout the body – leading to fatigue.

If not treated on time, the persistently low levels of red blood cells in the body might lead to the risks of megaloblastic anemia, leading to altered energy levels throughout the day.

2. Mouth Ulcers and Glossitis

Although not a common symptom with every patient, some report developing mouth ulcers inside the oral cavity. These are often painful and leave a burning sensation in the mouth, which amplifies when one eats something.

Another potent oral symptom of Vitamin B12 deficiency is glossitis. It is a condition that affects the tongue, changing its shape and color in the patient. Some report feeling tiny bumps all over their tongue, which often impairs the sense of taste and affects people’s appetite quite drastically.

3. Appearance of Pale and Yellow Skin

Noticing paleness or yellowing on the skin often redirects our mind into thinking that the patient has jaundice. While that could be a potential cause, even Vitamin B12 deficiency manifests as the appearance of pale and yellow skin.

Patients with a confirmed diagnosis of iron-deficient anemia are the ones at heightened risk of experiencing this symptom. The lack of mature red blood cells in the body leads to paleness all over the skin.

As we were talking about jaundice, did you know that Vitamin B12 deficiency can reportedly lead to jaundice as well? The lack of Vitamin B12 elevates the bilirubin in the body, further causing hemolysis in the body.

4. Prickling Sensation in the Body’s Extremities

Vitamin B12 has a very prominent impact on regulating nervous system functions. It plays an important role in the production of the myelin sheath. This fatty substance is responsible for acting as a buffer around the nerves to protect them from any external shocks, weather changes, etc.

Lack of Vitamin B12 impairs this process, leading to a prickling sensation in the tips of the finger and the legs. The condition is called Paresthesia and often manifests as an uncomfortable feeling throughout the day in the patient.

5. Persistent Headaches

Another neurological symptom of Vitamin B12 deficiency is experiencing a constant headache. Most people who have a reported history of migraine headaches are often low on Vitamin B12 in their bodies, as seen in multiple studies.

Although there is no solid evidence of the connection between Vitamin B12 deficiency and headache, more research is being done to establish a solid connection.

6. Stomach or Gastrointestinal Issues

The most alarming symptom of Vitamin B12 deficiency is a series of gastrointestinal complications, including nausea, constipation, gas, bloating, diarrhea, etc.

If you are constantly experiencing recurring “stomach issues,” it could be a sign of Vitamin B12 deficiency. In such cases, getting a formal diagnosis quickly is crucial.

However, another factor worth noting is that most GI symptoms are non-specific. This means that there could be other underlying complications contributing to the issue. The symptoms might be a side effect of medications, an active infection, etc.

You can look for any other symptoms that indicate a potential Vitamin B12 deficiency in the body. If that happens, it is ideal for getting comprehensive testing done for the safe side.

7. Depression and Depressive Symptoms

Studies have found that people with Vitamin B12 deficiency are at a heightened risk of being depressed. This is primarily due to the poor central nervous system function due to a lack of optimal Vitamin B12 availability in the body.

Vitamin B12 deficiency also leads to the progressive production of an amino acid called homocysteine, which might lead to oxidative stress, DNA damage, fatigue, tiredness, and reduced nervous system function in the body, thereby leading to depressive symptoms in the patients.

Even studies have confirmed the direct correlation between Vitamin B12 deficiency, homocysteine, and depression.

Although not very common, there are reports of patients with Vitamin B12 deficiency developing mood disorders and psychosis without proper treatment.

8. Reduced Cognitive Functions

Are you having a hard time focusing on certain things? If yes, it could indicate an undiagnosed Vitamin B12 deficiency. The reduced efficiency of the central nervous system leads to brain fog, which contributes to a lack of focus and concentration.

Such impacts often get worse with age, especially because the malabsorption of Vitamin B12 happens more as one ages.  Studies have found that people with Vitamin B12 deficiency often experience mental impairment and reduced cognitive function.

However, the condition can improve with a timely diagnosis and supplementation, enabling the patient to have a better quality of life.

9. Muscle-related Complications

Vitamin B12 might contribute to potent muscle cramps and weakness, due to impaired motor and sensory nerve function in the body.

If not treated on time, these muscle-related symptoms might get worse over time, leading to complications of Ataxia or poor balance and coordination in the patient.

Most people with Vitamin B12 deficiency experience poor muscle coordination and have a hard time walking in a straight line or balanced posture when they are walking around.

10. Other Potential Symptoms

Besides these primary symptoms of Vitamin B12 deficiency, there are a few accessory ones worth mentioning as well.

Most men with Vitamin B12 deficiency report experiencing erectile dysfunction, especially due to the elevated production of homocysteine in the body.

Furthermore, a lack of optimal Vitamin B12 levels might also contribute to vision problems, leading to poor eyesight or experiencing pain and numbness in the area. This happens due to the affected functions of the optic nerve in the eyes.

In rare cases, Vitamin B12 deficiency might also lead to personality changes. This isn’t a very common symptom but one that deserves mention in the list.


What happens if your B12 is dangerously low?

Dangerously low Vitamin B12 can lead to severe GI-related symptoms like constipation, gas, diarrhea, etc. Besides that, it might also augment the complications of Paresthesia and other mental health-related complications.

What is the fastest way to fix B12 deficiency?

The fastest way to fix a Vitamin B12 deficiency is with supplements. It involves the use of cyanocobalamin, which is prescribed in certain dosages depending on the degree of deficiency in the patient.

Which fruit is rich in vitamin B12?

Banana has the highest amount of Vitamin B12, which might combat the deficiency to a certain extent if eaten daily.


Vitamin B12 deficiency is a very serious clinical complication. If you are experiencing any of these alarming and early symptoms, it’s ideal to discuss the issues with a doctor is ideal. Your doctor will likely prescribe a Vitamin B12 analysis test based on the symptoms to check the levels.

Getting the test done without delay can drastically alter your quality of life. Not only does it guarantee a potential diagnosis, but it also means that you can get the relevant treatment to treat the Vitamin B12 deficiency and eliminate the symptoms for good. Prioritize testing in this case without any further questions.


Prekshi Garg is a young, dynamic, energetic, and meritorious professional biotechnologist. She is a merit rank holder in her post-graduation and a skilled bioinformatician with great zeal to do her best in neurosciences. She is currently working in the area of Neurotranscritomics dealing with neurodevelopmental and neurodegenerative disorders. She has presented many papers at different scientific forums and is awarded ‘Representing the Institution in Scientific Events’ citation by Amity University Uttar Pradesh and Top position in Student Assistantship Program held at Amity University in addition to awards won for oral presentations in different scientific deliberations. Prekshi has published a good number of papers and book chapters during the start of her academic career itself. Her tremendous skills and knowledge make her a good blend of biotechnology and bioinformatics.

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