What is vitamin B12 used for and where is it found?

Cobalamin is one of the body’s most important micronutrients, both among adults and children. It performs a wide selection of functions such as energy production or improving the nervous system. Whether you are on a vegan or vegetarian diet or simply concerned about having adequate levels of this micronutrient, this will interest you. The following explains in detail what vitamin B12 is used for and where it is found.

For what is the vitamin B12?

The function, or rather, functions of the B12 is of special importance to our organism. It has many benefits, but some of them are essential. Also, other nutrients in the group share some functions with this one.

Vitamin B complex

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The group of vitamins B consists of B1, B2, B3, B5, B6, B8, B9 and B12. The following explains in detail what each one of them consists of and what is its function in the organism.


B1, also known as Thiamine. The body does not absorb this nutrient as such; vitamin B1 is transformed into a coenzyme that intervenes in the metabolism of carbohydrates. Other functions attributed to this B-group vitamin are the formation of RNA and DNA, as well as the stimulation of appetite. It also helps to keep the nervous system in good condition. For athletes, it is one of the most important vitamins to keep pace, so many opt for vitamin B1 supplements in combination with others. Foods rich in this nutrient are: wheat germ, beans, spinach and kale.


B2, also known as riboflavin, acts as a coenzyme. It plays a leading role in energy production. This nutrient is also very important for tissue to be maintained in good condition. Vitamin B2 also acts as an antioxidant, protecting the skin from free radicals such as pollution and UV rays. Foods rich in this vitamin group B are: eggs, spinach, wild rice and almonds.


B3, or niacin, intervenes in the metabolism of carbohydrates, being very important in the production of energy. One of its most important functions is that it helps to keep LDL cholesterol levels at bay, bad cholesterol; therefore, one of the great benefits of this nutrient is that it prevents cardiovascular diseases. Vitamin B3 also helps to keep the liver, skin and nervous system in good condition. This B group vitamin can be found in the following foods: yeast, milk, eggs and green vegetables.


B5, also known as pantothenic acid, releases energy from fats, proteins and carbohydrates. It plays a fundamental role in skin health as it significantly reduces signs of aging, such as wrinkles or fine lines. This is why many cosmetics are enriched with vitamin B5. This nutrient is found in large quantities in the following foods: avocados, yoghurt, meat and vegetables.


B6, also known as pyridoxine, is one of the most important nutrients in the body. It fulfills several essential functions for good health. On the one hand, it is involved in the production of red blood cells, which are responsible for transporting oxygen to the cells. On the other hand, it participates in the production of hormones and neurotransmitters such as serotonin or melatonin, so it is a nutrient that helps to improve the symptoms of diseases such as depression. And finally, it is in charge of energy production. Foods rich in vitamin B6 are: salmon, cheese, rice and carrots.


B8, or biotin, is involved in the formation of glucose from carbohydrates. It is directly linked to the health of hair, skin and nails. That’s why vitamin B8 is also known as the beauty vitamin. In addition, for pregnant women, it is important to maintain good levels of vitamin B8 because this nutrient is involved in the baby’s growth.


B9, also called folic acid, is found mostly in the leaves of vegetables. An essential nutrient in tissue regeneration. It also plays a very important role in the formation of RNA and DNA. During pregnancy, it is the most important vitamin of all because it prevents as far as possible premature birth and any kind of malformation in the fetus. Foods rich in vitamin B9 are: asparagus, beet, salmon, wheat and milk.


B12 or cyanocobalamin is largely responsible for energy production, which is why people who suffer from deficiency of this nutrient suffer mostly weakness and fatigue as the main symptom. This B-group vitamin is involved in the conversion of carbohydrates into glucose. It also has another wide range of functions in the body, such as improving the nervous system and cardiovascular system. It is also extremely beneficial in improving the symptoms of certain mental illnesses such as depression.

What is vitamin b12 benefits and functions?

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Also known as cobalamin, it is only necessary for the body in small amounts. In spite of this, it performs functions that are absolutely essential for the proper functioning of the system. These functions are explained below.

Red blood cell formation

This is the most important function it plays in the body. Red blood cells carry oxygen throughout the body. In addition, red blood cells are responsible for feeding nutrients to cells.

DNA and RNA formation

It is in charge of making part of the genetic material of our body, a really important function to not leave aside the correct consumption of this vitamin.

Transformation of fatty acids into energy

The best known function of all is to provide energy and vitality. This nutrient transforms the fatty acids of the organism into energy. This is why people with cobalamin deficiency have fatigue and weakness as their main symptom.

Nerve fiber sheath formation

Vitamin B12 plays a very important role in the functioning of the nervous system at all levels.

Stimulation of osteoblast activity

It is one of the most unknown functions of this vitamin in the B group, but undoubtedly one of the most important, especially in children and the elderly. Cobalamin stimulates the activity of the cells responsible for bone formation. Therefore, it is a key nutrient for ensuring good bone health.

Functioning of the immune system

It plays a key role in the proper functioning of the immune system. Thus, maintaining good levels of this nutrient in the body, people are more and better protected against any type of viral disease such as flu.

Many of these functions can be seen to be fulfilled by other vitamins in the B group or complex, as they are similar and complement each other. While this does not at all mean that we can substitute one for another; they are all special and have their specific functionality in the right dosage.

Benefits – Why is it important to know why vitamin B12 is good?

Although there is little or no mention of vitamin B12 and its importance for the proper functioning of the body in general society, it is advisable to know what it is used for and what its functions are. Thus, being aware of how important it is to enjoy a good state of health, its regulation is simpler, as well as the taking of the appropriate quantities.

There are certain pathologies that can make it difficult to absorb them; thus, people who suffer from them know of their importance and are concerned about going to the doctor to develop a plan to take this nutrient suitable for them. Similarly, vegans and vegetarians know that the vast majority of cobalamine-rich foods are of animal origin and that they should go to a nutritionist who will advise them on what kind of supplements they can take to make up for this deficiency.

Knowing this, we become aware and are able to regulate it and take the appropriate amounts, we worry about designing a diet, go to the doctor for advice, take supplements if necessary, carry out regular check-ups… in short,  knowing what B12 is used for gives us a plus to make correct decisions regarding consumption and the appropriate levels of this vitamin.

The deficit of this micro-nutrient is a serious pathology that requires immediate medical attention. In the first world, 80% of people suffering from vitamin B deficiency are vegan or vegetarian, since the foods that contain the highest amount of vitamin B are of animal origin.

Symptoms of vitamin B12 deficiency are:

  • Mental confusion
  • Weakness
  • Tingling
  • Numbness in extremities
  • Mood swings
  • Nausea

And although in other circumstances these may be related to other problems, knowing that you follow a diet without food of animal origin makes all eyes immediately turn to cyanocobalamin.

Just as their lack is extremely dangerous for health, especially in certain population groups, their excess is also negative. It is usually given in patients with various pathologies such as liver disease (cirrhosis) or stomach disease.

The symptoms that lead to excess cobalamin poisoning are as follows:

  • Skin rashes
  • Vomiting
  • Headaches, headaches
  • Insomnia
  • Nervousness
  • Paralysis

What foods are vitamin B12 found in?

This micronutrient is stored within the liver as adenosylchobalamin, in reserves of 2 or 3 milligrams, sufficient to ensure proper functioning of the body for approximately two to three years.

In this way, people who suffer from vitamin B deficiency do not begin to show symptoms after two or three years; however, during this period of time functional alterations are taking place, which go unnoticed. That is why continuous medical check-ups are so important.

Although it is primarily stored in the liver, all cells have small amounts of this nutrient; kidneys, heart, brain, brain, muscle, melsae, erythrocytes, and other parts of the body.

Foods rich in vitamin B12

It is very important to be aware of the dose of vitamin B12 needed to ensure adequate levels of this nutrient in the body.

Therefore, vegans and vegetarians need to take this vitamin B group supplement obligatorily.


Meat contains a lot of vitamin B12, especially viscera. Veal liver provides 100 micrograms per 100 grams of food; in the case of lamb and chicken liver, 84 and 56 milligrams respectively. Lean beef cuts and tenderloins are also ideal to include in a healthy and balanced diet, as is chicken breast.


As for fish, the vast majority of them have very good levels of cobalamin, making them a fantastic option for taking the recommended daily dose of this nutrient. In addition, fish is a type of easily digestible food. The species that have the most are tuna, salmon, herring, mackerel and sardines.


As for the mollusks, oysters, clams and mussels take the palm. They also add variety to the diet so they can’t be more suitable.

Milk and dairy products

Among dairy products, cheese is the one that provides the most to the body. Depending on the type, the amount of cobalamin varies, although 30 grams of the appropriate cheese provides 1 microgram of this nutrient.


In the case of eggs, the contribution is found in the yolk of the eggs, providing between 1 and 1.3 micrograms per L class egg.

As can be seen, all foods with higher amounts of vitamin B12 are of animal origin. There are foods of plant origin that contain it, but in very low amounts. Therefore, it is impossible to obtain the recommended daily dosage for the organism through a plant only diet. For vegans and vegetarians, supplementation of this nutrient is an imperative.

Infography: Foods rich in Vitamin B12

Infografia de los mejores alimentos con cianocobalamina

*Weight equivalents: 1 OZ = approx. 28 gr.

Types of B12 Supplements – What is B12 dosage?

Vitamin B12 supplementation is key primarily in two situations. On the one hand, vegetarians and vegans who, by not consuming food of animal origin, cannot cover the recommended daily amount of this nutrient. On the other hand, people with some kind of pathology that makes it difficult to absorb, assimilate, synthesize or store this nutrient.

The following formats are available:


It is the most common format of all adults. Although very comfortable to take, it is not suitable for people with stomach problems because your body will not absorb the amount of pills properly.


Sublingual group B vitamin supplements are becoming more and more common. One of its main advantages is that the organism assimilates the nutrient very quickly and easily. Within seconds of placing the supplement under the tongue, it dissolves in the mouth and is immediately absorbed by the body.

Nose gel

Nasal gel is another way of providing this micronutrient to the body. It is usually used once a week. It enters the blood through the mucous membranes of the nose, so it is one of the best options for people who cannot absorb it into the intestine.


Vitamin B12 can also be injected into the body. Like the nasal gal, it reaches directly into the bloodstream. An alternative for people with malabsorption problems and others.


The drops are rarely used, especially for administering vitamin A to children or people with swallowing problems. Their handicap is that it is difficult to keep an exact control of their consumption.

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

It can be taken naturally through food. The largest amounts of this nutrient are of animal origin; although it is true that there are food of plant origin that contain cobalamin, the amount of this micro nutrient that is in them is minimal and does not reach the recommended daily dose.

In short

Vitamin B12 plays a fundamental role in the proper functioning of the body. It fulfills a wide range of key functions to enjoy good health, both physically and mentally. It is therefore very important to become aware of what this micronutrient does for health and to ensure that the recommended daily allowance is taken according to the population group.

In the case of vegan or vegetarian people, as well as others who suffer from a disease that prevents any organ from performing its function correctly with respect to the nutrient, it is recommended that they contact a specialist, nutritionist or doctor to treat the situation and design an adequate and personalized diet for each individual.

If it cannot be taken through food, there is a wide range of possibilities for taking it through supplements, but, however, it must be consumed and transformed for the body to use it properly.

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Did you really know what B12 and all its benefits are for your body? Express your doubts, experiences or advice, together we help more people who read the blog every day!

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