Functions and properties of vitamin B12 in our human body

Much is said about vitamin B12. And the truth is that it is no less because it has a key role in the proper functioning of the organism, both to perform essential functions and providing a multitude of secondary benefits. Cobalamin has a broad spectrum of functions such as energy production, relieving symptoms of depression or improving the nervous and cardiovascular systems, to name a few. Vitamin B12 was discovered not long ago. Despite its important role in the proper functioning of the organism, this nutrient has been one of the most important nutrients to discover its structure.

It was in 1956, following a research study on pernicious anaemia. It is a type of anemia caused by the body’s difficulty absorbing B12. Some of the most frequent symptoms of pernicious anemia are tiredness, memory loss and other cognitive disorders that we happen to see in those people who suffer from lack of this nutrient. In the following sections we explain a wide selection of very interesting concepts about this vitamin; the main functions and the most positive benefits it has in the organism, as well as the population at risk of micronutrient deficiency and the consequences of this pathology.

Vitamin B12 and its functions in the human body

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Functions of Vitamin B12 for the health

The main properties of vitamin B12 in our body are as follows:

Bone marrow

This nutrient plays a key role in bone marrow regeneration. Vitamin B12, along with iron and folic acid, participates in the formation of healthy blood cells.


One of the best known functions of B12 is that it helps to improve the symptoms of diseases such as depression by participating in the production of serotonin and other neurotransmitter substances. Therefore, it is a nutrient of special importance for both physical and mental health.

Cardiovascular health

It is not a well-known function because there are other vitamins that also work the cardiovascular system, but this micronutrient is very important for good heart health. Along with folic acid and B9, it lowers homocysteine levels, a risk factor for heart disease. People treated with B12 have fewer heart problems and stroke.


In neuropathies, having adequate levels of this vitamin can reduce nerve pain, numbness and tingling of limbs. This is why in people with vitamin B12 deficiency, one of the main symptoms is numbness and tingling of the arms and legs.

This vitamin is responsible for keeping the myelin in good condition, that is, it not only helps the elements of the nervous system work better but also keeps them in good condition.

Red blood cells

Vitamin B12 participates in the production of red blood cells, synthesizing them. They transport oxygen to the blood and hence to the cells, which is why it is so important to maintain the right levels of cobalamin.

Genetic material

DNA and RNA are best synthesized with a good amount of B12; in fact, it helps make nucleic acid. This aspect is of vital importance during pregnancy, so that the fetus develops perfectly.


In order to properly metabolize food, it is necessary to have a sufficient dose of B12 in the body, otherwise, this property cannot be carried out and the metabolism slows down; hence many companies inflate this benefit to sell products that promise to lose weight and are composed, in part, of cobalamin.

This micronutrient is also essential for the overall good functioning of the body, both in older adults and children. This is because, in general, cyanocobalamin is needed to keep cells throughout the body healthy.


It has also been proven that a correct dose of cobalamine prevents and treats many menstruation-related conditions.


It is part of the synthesis of creatine. This, in turn, is responsible for maintaining muscle mass at a good level as well as an optimal amount of energy in the body.


Another of the main functions is to convert carbohydrates into glucose, which is the form of energy that our body needs to carry out its properties and not tire in situations of effort.

These 11 functions or properties of vitamin B12 are the best known and most important, although there are some other secondary functions or properties.

Risk populations due to lack of B12

Vitamin B12 for vegans and vegetarians

Although vitamin B12 plays such an important role in the proper functioning of the body, B Complex vitamins deficiency is a relatively common condition, although in the first world it does not occur in a really serious way, it can be worrying in some cases.

Vegetarians and vegetarians

One population group at risk are vegans and vegetarians. It should be borne in mind that the vast majority of foods rich in B12 are of animal origin, such as meat, fish, molluscs, milk or eggs. There are also plant-based foods that contain this vitamin, albeit in very low amounts, which do not cover the minimum daily amount at all.

In the case of vegans, who do not take any animal products of their own free will, cobalamin deficiency can become a serious pathology in the medium or long term if no such nutrient supplements are taken.

As for vegetarians, who restrict only meat and fish, although if they eat other foods such as milk or eggs, the lack of this micronutrient is an equally common but less serious condition. Even so, taking vitamin B12 supplements is mandatory in all cases if you want to have enough levels for our body to correctly perform all these functions that we have discussed.

A 2013 study of how much vitamin B12 deficiency there is among vegans and vegetarians shows very interesting data. The study was published in the journal “Nutrition Reviews”. Well, this one revealed that:

  • In the case of children, between 25 and 86 percent of them lacked this nutrient.
  • In the case of adolescents, the percentage was between 21 and 41 percent.
  • The adult vegetarian or vegan population had vitamin B12 deficiency in 11 to 90 percent of cases.

From these figures it can be inferred that, in fact, there is no control over the nutrients that are taken in vegetarian diets, since the percentages are so large that it is impossible to delimit a pattern or make a statement that goes beyond the mere fact of knowing that people who follow special diets very often suffer from lack of various nutrients, such as cobalamine.

The study found higher rates of micronutrient deficiency among vegans than among vegetarians, who, as we have said, consume eggs and/or dairy products. In addition, deficiency rates were higher among those who were vegetarians from an early age, so it is vital to inform the population who opted for this type of diet, that B12 supplementation becomes absolutely essential.


One group of the population most likely to suffer from vitamin B deficiency are the elderly for two reasons. On the one hand, as people get older, their appetite is reduced; therefore, in many cases, they do not take the necessary food to ensure the recommended minimum daily intake of B12. And, on the other hand, in old age the stomach has less capacity to both receive and process food, so the little or too much B12 they receive, as well as the rest of the nutrient, is processed worse.

In the second case, if there are elderly people who have trouble absorbing vitamin B12 from the foods they eat, the doctor may choose vitamin B12 supplements that are given directly into the bloodstream, such as nasal gels or injections.

People who prescribe certain medications

Taking certain medications, for example to treat ulcers, also reduces the stomach’s ability to absorb this vitamin. Medications designed to reduce stomach acid production may also interfere. For this reason, anyone who has chronic medication of these is likely to end up suffering from a cyanocobalamin deficiency.

Vitamin B12 deficiency

Anaemia is, in the great majority of cases, the first symptom of deficiency of this micro-nutrient. It should be borne in mind that vitamin B12 is essential for the proper functioning of the body, both physically and mentally. Thus, a lack of it can generate a wide range of relatively serious symptoms:

  • Lack of sensation or tingling in the arms
  • Memory loss
  • Disorientation
  • Depression
  • Mood changes

Deficiency of this micro-nutrient is most common in the following population groups:

  • Celiac disease: This deficiency is very common in celiac people, who are intolerant to gluten. In a recent investigation, they found that 20% of all coeliacs suffer from a greater or lesser degree of vitamin deficiency. For this reason, it is essential to take the necessary measures to make up for this deficiency by means of supplementation.
  • Dementia: Diseases such as Alzheimer’s have a very close relationship with this deficit. Patients with Alzheimer’s disease have been found to have a lower concentration of vitamin B12 in the brain spinal fluid than healthy people. Being deficient in this micronutrient over a long period of time can decrease brain tissue. Today, a wide range of research is underway around the world looking for new ways to administer B12 to slow the progression of Alzheimer’s disease.
  • Depression: This vitamin plays a fundamental role in physical health, as well as mental health. More than 30% of patients with severe depression have low blood levels of B12. Thus, supplements of this nutrient are sometimes effective in improving the symptoms of depression.
  • Cardiovascular diseases: Some studies have shown that this deficiency causes elevated homocysteine levels in people over 60 years of age. Homocysteine is one of the main risk factors for cardiovascular diseases such as heart attack. Thus, supplements or a diet rich in this nutrient decreases the level of homocysteine in the blood.
  • Pernicious Anemia: Today, about 2% of people over 60 suffer from pernicious anemia. In these cases, the most effective solution is B12 injections.

And underdeveloped countries?

In 2016, hunger increased again after 13 years of decline. It affects an estimated 815 million people, 11% of the world’s population. The main reasons for this increase are conflicts and natural disasters. The world’s most hungry areas are in sub-Saharan Africa, South-East Asia and West Asia. For chronically malnourished people, the figure has increased from 777 million in 2015, but remains below 900 million in 2000.

Hunger causes a large number of deaths worldwide each year, chronic illnesses and many others. There are children who suffer the consequences of having low B12 from birth; lack of vitamin B12 in pregnancy can trigger malformations in the fetus, as well as problems at birth for the father.

During infancy, a continuous lack of this important nutrient for the organism can cause a series of pathologies to the youngest as problems in the development or loss of brain mass; serious illnesses with both short and long term consequences.

For adults, lack of vitamin B12 can lead to a wide range of symptoms:

  • Weakness
  • Muscle numbness
  • Depression
  • Lack of energy and vitality
  • Loss of brain mass
  • Dementia

How to prevent vitamin B12 deficiency?

B12 Supplements for vegans and vegetarians

Preventing these deficiencies is relatively simple, as long as you have access to sources of food rich in this nutrient and/or supplements. The most important thing is to have regular medical check-ups for, if there are low levels of vitamin B12 in your blood, to be able to detect them early. In this case, the medical staff can act by designing a diet rich in cobalamin or treating the situation with supplements, always depending on the characteristics and needs of each patient.

Only in this way will we be able to make sure that everything works properly in our organism, and therefore, we will enjoy its benefits, which are numerous and very important.

Dietary Reference Values for cobalamin (vitamin B12)


Quantity (mcg*)

Up to 6 months

0.4 mcg

From 7 to 12 months

0.5 mcg

From 1 to 3 years

0.9 mcg

From 4 to 8 years old

1.2 mcg

From 9 to 13 years old

1.8 mcg

14 to 18 years old

2.4 mcg


2.4 mcg

Pregnant women

2.6 mcg

Breastfeeding women

2.8 mcg

Depending on these amounts it will be possible to design an adequate diet or opt for vitamin supplements with various vitamins and other nutrients if necessary.

Take supplements, yes or no?

Cobalamin supplements can be found on the market at will; a 100% recommended alternative for vegan and vegetarian people, as well as for those who, for whatever reason, do not properly absorb this nutrient. No supplement of this vitamin has any animal origin. All B12 supplements are synthesized in a lab.

There are many different formats when taking this supplement. For people who suffer from illness or are taking a medication that blocks absorption of vitamin B12 by the body, it is best to bet on nasal gels or injections because the micronutrient passes directly into the bloodstream. However, it should be noted that these require a prescription.

Vegetarians or vegans may opt for vitamin B12 tablets

Be that as it may, the important thing, as we have already mentioned, is to take the micronutrient so that the properties of this vitamin are given in our organism and it works perfectly.


It is really important to be aware of how important vitamins are to our health. Continued medical analysis will be essential to detect any type of alteration in the medium or long term and, above all, to determine which treatment to start as well as to see the advances.

Vitamin B12 is mainly stored in the liver and has a life span of 2 to 3 years, which is why many people who suffer from lack of this nutrient do not notice any symptoms until after that time, although this deficiency has already altered numerous functions in the body. Therefore, prevention is key.

To be healthy, it is important to eat a variety of fresh foods. In addition, a healthy and balanced lifestyle must be followed. A diet rich in fruits and vegetables, but also animal foods that cover the recommended daily allowance are necessary.

Only in this way will B12 be able to perform the multiple, beneficial and necessary functions for our organism to function properly.

It is also important to exercise in low or moderate intensity three to four times a week. Mind must also be taken care of. To do this, stress should be avoided as much as possible, and meditation exercises should be practiced frequently.

In any case, if we want to enjoy a proper execution of the properties and functions of vitamin B12, it is essential that it be synthesized in our organism, either by taking it in a healthy diet or by means of supplements.

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Did you know all the functions and properties that this vitamin gives us for health? You can comment, give your experience or raise your doubts, surely the readers appreciate it

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