Keep An Eye on Vitamin B-12 Deficiency Symptoms

A girl lying in the bed is holding a mobile.

Vitamin B12 deficiency (also known as cobalamin), is a water-soluble vitamin that is derived from animal products such as red meat, dairy, and eggs (1)

It is an essential vitamin that plays a role in producing red blood cells and DNA in the body, also the development of brain and nerve cells.

Once absorbed, vitamin B12 is used as a coworker for enzymes that are involved in the synthesis of deoxyribonucleic acid (DNA), fatty acids, and myelin (2).

B12 is stored in most parts of the liver, however in cases where B12 cannot be absorbed for a long time (e.g, dietary insufficiency, lack of intrinsic factor), hepatic stores are emptied, and deficiency occurs (3) (4) (5).

Its deficiency can lead to serious issues like anemia, damage to the nervous system, and other complication (6).

But there are symptoms of deficiency you can watch out for to determine when it’s time to visit your doctor.

Here are 10 symptoms of vitamin B12 deficiency that you shouldn’t ignore.


A study showed that vitamin B12 is often used to improve fatigue (7).

In analyses, data showed that vitamin B12 deficiency was significantly and independently associated with the presence of severe fatigue and clinically significant depression (8).

As we know that vitamin B12 is vital for the production of red blood cells (transport oxygen throughout your body).

When there aren’t enough red blood cells (RBC) in the body, there isn’t enough supply of oxygen, as a result, you will feel fatigued or weak.

Insufficient RBC in blood also leads to anemia (a condition where the body lacks enough healthy RBC, which can lead to irregular heartbeat, and it can become a risk of a heart attack.

Weight loss or gain

A Human reported observing that about 2.1 billion (30%) humans worldwide are obese or overweight, which also contributes to 5% of global mortality (9).

A study showed that vitamin B12 level was significantly low in obese and overweight people, but not with insulin resistance, metabolic syndrome, and gender (10).

In a review of clinical data, although not conclusive, lower concentrations of Vitamin B12 were observed in obese people compared to overweight and normal-weight people.

Another study found that pregnant women shown with low vitamin B12 in the first trimester had increased BMI compared with those with normal B12 levels (11).

Check OUt – Unspecific 10 Reasons Why You Losing Weight

Shortness of breathing

Some studies have found that a vitamin B-12 deficiency may be linked to increased levels of homocysteine—an amino acid associated with cardiovascular disease.

A self-reported doctor-diagnosed found that folate deficiency is associated with asthma and attacks of shortness of breath, but not with lung function or atopy (12).

Vitamin B12 may also be false in patients with liver diseases, myeloproliferative disease (where bone marrow make too many RBC, WBC, and platelets), and long-term nitrous oxide exposure.

Numbness on hands and feet

Severe deficiencies can cause nerve damage that could result in tingling sensations in your hands and feet as well as pins and needles feeling in your legs.

Studies have shown that Poor B12 is associated with worse sensory and motor peripheral nerve function (13).

Now, as we know, nerve damage is quite common with vitamin B12 deficiency, and a common side effect of nerve damage is a feeling of numbness or tingling in your hand and feet.

B12 plays a vital role in the production of myelin, (a fatty substance that surrounds the nerves to provide both insulation and protection)

Insufficient vitamin B12 produces less myelin, which affects the nervous system and can result in those tingling sensations that you may be feeling

Another study showed that many adults and kids who have B12 deficiency were reported to experience numbness (14) (15).

Stomach Issue

In this, a girl is shown holding her stomach

Our digestive tract can also be affected when our body is not taking in enough vitamin B12. with fewer RBCs, there is less oxygen reaching our gut.

A lack of oxygen in this area can result in nausea and diarrhea.

The stomach plays a vital role in both absorption of B12 and the pathogenesis of cobalamin deficiency (16)

A study showed that B12 deficiency may also cause diarrhea, nausea, constipation, bloating, gas, and other stomach issues (17) (18).

Check Out – Constipation In Children, What Are The Things You Should Take Care Of?

May cause symptoms of depression

Depression is a very common mood disorder, resulting in a loss of social function, reduced quality of life, and increased mortality (19).

A study shows that vitamin B12 deficiency is allied with irritability, personality change, depression, dementia, and psychosis rarely (20).

Muscle weakness in arms or legs sudden difficulty walking new problems with vision dizziness feelings of anxiety and depression can also be a sign of a vitamin B-12 deficiency.

A researcher-reviewed study published an article showing that low vitamin B12 deficiency is associated with an increase in depression (21).

Another study showed that B12 supplement with antidepressants significantly improved depression in a cohort (a group of people who are around the same age) like college students).

Check Out – Is Music Can Treat Mental and Physical illness?

Yellow skin

Having pale or yellow skin is associated with jaundice, but vitamin B12 deficiency is also to blame.

Jaundice in newborn babies is a most common health issue, especially seen 1 week after birth, it happens due to the high amount of bilirubin, which is found in RBC and causes jaundice.

The yellow color is caused by high levels of bilirubin, (a waste product created when your body breaks down red blood cells) (22).

As we told earlier, a lack of B12 means – less supply of red blood cells in your body, this slows down the process of cell building and prevents them from dividing.

without sufficient RBC in the body, there isn’t enough circulation of oxygen, this is why you get pale skin.

Check Out – How Does Light Therapy Treat Jaundice?


As we previously mentioned that vitamin B12 deficiency leads to anemia, which can result in a feeling of shortness of breath, over time this can make you feel lightheaded and weak.

A study showed that Vitamin B12 deficiency can also lead to dizziness and syncope (feeling unconscious) (23).

Dizziness is a common indicator that your body is low in vitamin B12.

NOTE: It all goes back to a lack of production of RBC in the body.

A rise in the vitamin B12 levels in the body can help bring things back to normal, this is unless you have a serious case of depression.

Moreover, dizziness can also happen due to ear disturbance, motion sickness, medication effects, and any underlying medical condition.

Alzheimer disease

The study showed that folic acid and vitamin B12 can prevent dementia and Alzheimer’s disease and also improve brain function (24).

According to the study patients with Alzheimer’s disease have shown lower vitamin B12 levels and higher homocysteine levels as compared to patients without dementia.

Low Vitamin B12 is also allied with poor myelination, which promotes homocysteine levels and may be allied with Alzheimer’s disease, cardiovascular disease, and stroke (25) (26).


Some people who are deficient may not experience any symptoms at first, but over time they can develop memory problems or dementia.

If you think you might be deficient, talk to your doctor about getting tested, especially for those who are vegan or vegetarian (since meat is a great source of B-12)

In addition, there is not enough vitamin B12 to make RBC, which also reduces the oxygen supply to the brain, this decreases your brain’s ability to think and reason.

Some people may even get memoryless because of this problem.

One study showed a link between cognitive impairment (where a person may have a hard time concentrating, thinking, or reasoning) and vitamin B12.


All these symptoms can point to other serious health conditions, so talk to your doctor about whether your vitamin levels could be related.

If you have any symptom that concerns you, have them checked out by your primary care physician.


Hello, I'm Sahil bisht, I am a Mechanical engineer, As well as, aspiring blogger with an obsession for health. This blog delicate to people who want to learn in health.

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