Vitamin B12 or Cyanocobalamin: What is it and what is it for?

Cobalamin or cyanocobalamin is one of the most important nutrients in the body since it plays a leading role in the production of red blood cells, as well as in the proper functioning of the nervous system. However, this micro-nutrient is much more. We will talk about foods rich in vitamin B12, which are mostly of animal origin, alternatives and provide some reflections on their importance.

In the following sections we will explain everything you need to know about vitamin B12:

  • History
  • Main functions
  • Benefits for the organism

History of vitamin B12 or cyanocobalamin

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Cyanocobalamin, despite having an essential role in the proper functioning of the body, was the last vitamin to be discovered by science. Its study began in 1849, much later than the exploration of other nutrients.

Chemical compound

Cyanocobalamin Formula

  • Molar mass: 1355,365177 g/mol
  • Number CAS: 68-19-9
  • Other names: Cobalamin
  • Semi-developed formula: C63H88CoN14O14P
  • Solubility in water: 3.84e-02 g/l mg/mL (20 °C)
  • Melting point: -300 °C (-508 °F)
  • Average life: About 6 days; 400 days in the liver

Cyanocobalamin was the first synthetic form of cobalamin, created in a laboratory. Most vitamin supplements of B12 contain cyanocobalamin. These supplements are available in a variety of formats, from nasal gels, pills or pills to even an injectable liquid. You can buy cyanocobalamin alone, added in multivitamin complexes or in a much more recommendable vitamin B12 complex.

The first to take an interest in this B-complex vitamin was Thomas Addison, a renowned British doctor. The doctor noted that many of his patients shared the same symptoms for no apparent reason:

  • Weakness
  • Pallor

In 1860, Austin Flint, an American physician, associated these symptoms with a gastric system problem. It wasn’t until 1872 that Bierner linked them to “pernicious anemia”.

The reports produced over several years served as the basis for the first theory on the treatment of this pathology by two Boston doctors, George Minot and William Murphy, in 1925. Such was their contribution to medicine that they won the Nobel Prize.

The next discovery of vitamin B12 came from William Bosworth Castle at Boston City Hospital in the 1920s. The doctor found that the anemia suffered by many of his patients was caused by an “intrinsic factor,” which was indispensable to absorb the “extrinsic factor”.

Years later, after numerous investigations, this “intrinsic factor” was discovered to be a glycoprotein produced by the walls of the stomach. Thus, when it came into contact with the “extrinsic factor”, vitamin B12 allowed its absorption.

In 1948, Mary Shorb, in a project with Karl August Folkers and other team members, identified the “extrinsic factor” as cyanocobalamin. Several years later, Dorothy Crowfoot Hodgkin, along with a group of scientists, were able to determine the chemical structure of the molecule. This discovery earned them the Nobel Prize in Chemistry in 1964.

In 1972, Robert Burns Woodward, an American chemist and Albert Eschenmoser, a Swiss chemist, eliminated pernicious anaemia as a deadly pathology for the first time in history thanks to the wide range of discoveries made in the twentieth century.

Functions and benefits of cyanocobalamin: What is it and how does it help us?

Cyanocobalamin B12 formula

Just as with the vast majority of B-complex vitamins, vitamin B12 plays a key role in the normal functioning of the metabolism, so it is a key micronutrient in energy production. Enjoying good levels of vitamin B12 helps to significantly reduce both fatigue and fatigue, among many other benefits.

Vitamin B12 fulfils a wide range of functions in the body. The following explains in detail what these functions are and to what extent they benefit the proper functioning of the organism.

Improvement of depression symptoms

Vitamin B12 provides a wide range of benefits not only physically but also mentally. This nutrient plays a leading role in producing neurotransmitters such as dopamine and serotonin. These neurotransmitters are found at very low levels in people with depression. Therefore, this B-group vitamin helps the body to produce them, which noticeably improves the symptoms of depression and, in general, helps to improve mood.

Helps to develop the elements of the nervous system

This is one of the most well-known benefits of cyanocobalamin for the body and also one of the most essential and necessary.

This nutrient acts on myelin, a fatty material that covers the nerves of the body. Therefore, having adequate levels of vitamin B12, electrical impulses between the body’s nerve cells are best transmitted. The nervous system is extremely important for a good quality of life; it guarantees the proper functioning of the body, as well as stability and mental well-being, and with its care degenerative diseases are avoided.

Improved cardiovascular system

Cardiovascular diseases are unfortunately becoming more and more common. The number of people dying from myocardial infarction is increasing, especially in developed countries. The causes of this boom may be many, but one of the most relevant is a chaotic pace of life, combining personal and professional life.

On this point, to say that cyanocobalamin reduces, or rather, considerably regulates, homocysteine levels, which in many cases causes cardiovascular-related diseases when their levels are too high.

Improved fertility

It is one of the most unknown properties of vitamin B12, but at the same time it is also one of the most important. This nutrient is key to the fertility of both men and women. In addition, good levels of this micronutrient in the body during pregnancy are absolutely essential for them; otherwise, there can be problems in both the fetus and the health of the mother during pregnancy and childbirth.

Energy improvement

Virtually 100% of people with vitamin B12 deficiency have tiredness and weakness as the main symptom of this condition. This nutrient plays a key role in energy production. It is mainly responsible for the fact that we can continue with our daily life without feeling fatigued and that we can also stretch our physical activity sessions without feeling exhausted, which is why athletes usually take cyanocobalamin on a regular basis.

Tissue growth

Vitamin B12 also plays a very important role in both tissue growth and regeneration. This is therefore an especially important benefit for people who have a wound or burn. This nutrient is key to the healing process of the skin.

It also improves the internal muscle building, which makes the nutrient serve athletes twice as much because, as well as helping to create energy and improve its quality, also promotes muscle growth.

Metabolism development

There is also a lot of talk about vitamin B12 being used for weight loss. Well, it’s a half-truth. One of the main functions of this nutrient is that it activates the metabolism of the organism. Therefore, if we exercise, the effectiveness of exercise in losing weight will be much greater. However, vitamin B12 by itself does not help to lose weight as such. We need to lead a healthy lifestyle, with a balanced diet and continued exercise practice and with it, we will enhance the results naturally.

How is cyanocobalamin processed and assimilated?

Sistemas absorción y proceso de cobalamina B12

Cyanocobalamin production

It is important to know how vitamin B12 is processed in the body. The first thing to keep in mind is that it is a water-soluble vitamin, i. e. it dissolves in water. Neither plants nor animals can produce this vitamin, only bacteria and archeobacteria have the enzymes necessary for their synthesis. On the other hand, it should be noted that, from a structural point of view, vitamin B12 is the most complex of all vitamins.

First of all, it should be noted that human physiology in relation to vitamin B12 is extremely complex; this is why vitamin B12 deficiency sometimes arises as a pathology.

This nutrient is released from binding to proteins by digestive peptidases in the stomach and small intestine. Gastric acid is responsible for releasing the vitamin from particles in food. There are certain factors that can block this release, such as taking some diabetes-related medications.

It is the R proteins that bind to B12; they are produced in people’s salivary glands. Vitamin B12 binds to R proteins for pure survival; otherwise, it will degrade in the acidic environment of the stomach.

The next protein to bind is intrinsic factor FI, which is synthesized by gastric parietal cells. Once in the duodenum, proteases digest R proteins and release vitamin B12. In this way, vitamin B12 binds to intrinsic factor, forming the B12+FI complex.

Once the B12+FI complex is recognized by the receptors, it is transported to the liver support system. The vitamin is then transported to transcobalamin II, which distributes the plasma. Thus, for vitamin B12+TC-II to be useful for cells, the B12+TC-II complex must bind to a cell receptor; this is known as endocytosis.

A lysosome then degrades the transcobalamin-II so that vitamin B12 is released. Once released, the nutrient is released into the cytoplasm, where it is transformed into the correct coenzyme by cell enzymes.

Storage and stocks of B12 in the organism

The total amount of vitamin B12 that the human body stores is between 2 and 5 milligrams in adults. 50% of this amount is stored in the liver. It can also be stored in many other places, such as in the testicles, bone marrow, kidneys, brain, or pancreas.

The cyanocobalamin reserves last very long in the organism, between 3 and 5 years, depending on the characteristics of each individual. Although, after this time, they disappear, so it is necessary to take the nutrient on a regular basis. Still, we have to say that it is a generous vitamin in terms of the duration of its reserves; others must be renewed often.

This leads us to believe that, at least in the first world, cyanocobalamin deficiency is not a serious priority, although it is a phenomenon that occurs more often than we might think, especially in vegan or vegetarian populations that do not adequately supplement themselves with this micro-nutrient.


As for the excretion of vitamin B12, it is produced in bile. The good news is that much of it can be recycled in a process known as entero-hepatic circulation.


For a correct absorption of vitamin B12 by the body is essential to make a proper chewing of food.

In addition, it is important that exocrine cells in both the pancreas and small intestine are healthy. If there is any type of problem in either of these two organs, vitamin B12 deficiency could occur, a serious pathology that can even cause mental and neurological sequelae, not to mention physical problems.

Thus, people who do not have the intrinsic factor we talked about are more likely to have vitamin B12 deficiency because they are less able to absorb it. In cases of pernicious anemia, intrinsic factor is not present by autoimmune atrophic gastritis.

One of the population groups most likely to suffer from vitamin B12 deficiency is the elderly. Many older people have very high levels of folic acid in the blood because their parietal cells have stopped working properly. What does this mean? They expel 80 to 100 percent of the vitamin B12 ingested through the stool. A very high percentage considering that the vast majority of adults only expel between 30 and 60 percent, and always after having collected the right dose to transform it into the body.

Do you have low vitamin B12? Causes and possible risks

Cyanocobalamin deficiency is a fairly common pathology despite being a disease that can be very serious. About the causes of B12 deficiency, they can be many and varied.

This pathology occurs in many vegans and vegetarians. It should be noted that this micro-nutrient is found in food of animal origin. Vitamin B12 is also found in some plant-derived foods, although to a much lesser extent and is totally insufficient if the diet includes only plant-derived foods.

Other causes of vitamin B12 deficiency may include dietary factors, such as malnutrition in pregnancy or poor nutrition for children. Other causes include Crohn’s disease, celiac disease, pernicious anemia, or taking certain medicines to control heartburn.

What are the best sources of cyanocobalamin or B12?

Vitamin B12 intake is essential for the proper functioning of the body, both in adults and children. The recommended daily amounts are, depending on the age group:

Recommended daily allowance of Vitamin B12 according to EFSA


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

As far as the ways of taking cobalamin are concerned, we have the intake of cobalamin-rich foods, fortified foods and supplements.

Foods rich in vitamin B12

Below is a list of the foods that are richest in this nutrient.


  • Beef: Beef is the most vitamin B12 provides the body with the highest amount of vitamin B12. Its contribution per 100 grams is 2 micrograms for the leanest pieces. The meat with the highest vitamin B12 content is beef loin; 13 micrograms per 100 grams.
  • Chicken Breast: Chicken breast is a very rich source of vitamin B12, especially if taken cooked and skinless. The contribution of a medium sized chicken breast is 30 micrograms.


  • Salmon: Salmon is the species of fish that provides a greater amount of this vitamin to the body. No less than 10 micrograms per 150 grams, as long as it is consumed cooked. In addition, salmon is a very rich source of protein and Omega 3 fatty acids.
  • Tuna: Tuna is a very good option when it comes to providing the body with the amount of vitamin B12 necessary for its proper functioning. Its contribution is 3 micrograms per 100 grams.
  • Other fish that give you a sufficient daily dose of B12 with one serving are herring, mackerel or sardine.
    Roe is also rich and a great variety in the design of a diet.

Animal derivatives

The animal derivatives with the highest cyanocobalamin content are strong and cured cheeses, yoghurt, skimmed milk and egg yolk.


There are some very tasty mollusks that offer the amount we need in a generous ration. These are the clam, oyster and mussel, although there are more.

Fortified foods

In order to solve this very problem, people who do not include animal foods in their diet opt for foods enriched with B12.

At the present time we find some milk or soy drinks and fortified cereals; although, taking into account the progress of the consumer society, we will soon have an enormous variety of foods enriched with cyanocobalamin to satisfy the vegan and vegetarian demand.

Infography: 12 Foods rich in vitamin B12

12 foods with the most vitamin b12

Cyanocobalamin supplements

When it comes to taking vitamin B12 supplements, a wide range of formats are available. Which one to choose depends basically on the needs and preferences of each person.

  • Sublingual: These are sublingual supplements that contain a large amount of vitamin B12. The great advantage they offer is that the organism assimilates the nutrient very quickly and easily. As soon as you take the supplement, it quickly dissolves in your mouth and is absorbed.
  • Pills: Along with sublingual supplements, pills are one of the most common ways to take vitamin B12. They provide the recommended daily allowance that any adult needs.
  • Injections: The nutrient is injected into the muscle, so that the effect is immediate, skipping the entire process of the digestive tract. They need a prescription.
  • Drops: Vitamin B12 drops are the most recommended option for younger children. The drops of this nutrient do not contain the recommended daily allowance for adults, but they do for children. They are also a very simple format for the little ones to take. However, it is not easy to keep an exact control of the shots.
  • Nasal gels: Like injections, blood transfer is immediate, which is why they also need a prescription.

Please note that vitamin B12 supplements are suitable for vegans and vegetarians because they are bacterial in origin, not animal.

The Veganism Problem

As you have been able to see, the foods rich in B12 are of animal origin, those of plant origin do not have or their composition in cobalamin is minimal and insufficient.

We found that some algae such as dulse, kombu, akame or nori have some cyanocobalamin. There are also mushrooms such as the trumpet of death, shiitake or fungus of death will include some of that nutrient, but, as we say, the amounts are minimal.

Therefore, supplementation of this micro-nutrient is especially necessary to avoid vitamin B12 deficiency in vegan or vegetarian diets.

Conclusion about cyanocobalamin

As can be seen, this micro-nutrient plays a fundamental role in the proper functioning of the organism. Cyanocobalamin has a wide range of functions and properties to care for both physical and mental health.

It is important to take food and/or vitamin B12 supplements to ensure adequate levels of this nutrient in the body. It is essential to avoid, as far as possible, the deficiency of this vitamin B complex because the consequences for health can be harmful and, in addition, some of them chronic. Some studies have even shown that vitamin B12 deficiency leads to loss of brain mass.

This vitamin is one of the most important nutrients in the body, so it is essential to take it very seriously into account in your daily routine. In addition, a healthy lifestyle is key to good health, that is, an adequate and balanced diet, including all nutrients without exception, and frequent physical exercise. It is ideal to practice low or moderate intensity exercise three to four times a week.

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Did you know the importance of this vitamin in our body? If you have doubts, questions or can tell your experience, do not hesitate to comment, I am sure that other readers appreciate it.

If you found it helpful or have any questions, please comment and share, thank you! 😉

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