Vitamin b12 characteristics

Cobalamin or vitamin B12


Importance of Vitamin B12

Vitamin B12 or cobalamin is a water-soluble vitamin that is part of the B-complex vitamins. It was discovered later than other vitamins in 1948.

Vegetarian die

Vegetarian diet can be healthy but it is deficient in vitamin B12, so it would be advisable to take supplements

Although the amount of vitamin B12 that the body needs is very small, this element is essential given the importance it has in the proper functioning of it.

Vitamin B12 for anemia

At first it was considered that the only function of vitamin B12 or cobalamin was the correct formation of red blood cells, which are the blood cells responsible for the transport of oxygen.

Without this vitamin, the body can not transport oxygen and would produce pernicious megaloblastic anemia or anemia due to lack of B12, characterized by larger red blood cells of normal color (macrocytic and normochromic).

Because red blood cells are cells that are continually renewed, it is necessary for the diet to provide enough B12.

This vitamin was found in the liver of cows. With the addition of cow’s liver in the diet, green disease or pernicious anemia disappeared, a disease which, before this discovery, was very common, especially in older people and young women in the late nineteenth and early twentieth centuries. XX.

This type of anemia currently only appears in older people and people with diets that do not include any food of animal origin. It was called “green disease” because it was said that the skin of the affected people acquired that coloration.

Vitamin B12 to improve heart health

vitamin B12 supplements

Vegetarian people are advised to take vitamin B12 supplements because they are safe to take and avoid health complications

In addition to preventing the onset of anemia, it has subsequently been discovered that this vitamin is important for other functions of the body.

Without it, not only can anemia develop, but the nervous system, the heart, or our defenses do not work properly.

Good levels of vitamin B12 are necessary for a healthy heart and especially to prevent atherosclerosis or accumulation of cholesterol in the arteries.

Summary sheet of the properties of cobalamin or vitamin B12. It is a vitamin well known for its discussion of the deficit in vegetarians. Due to its important functions, even if the intestinal microbiota manufactures it in a certain amount, it is better to ensure a good contribution through supplements, which can prevent avoidable complications.

Properties of vitamin b12 or cobalamin

Summary sheet of the properties of cobalamin or vitamin B12. It is a vitamin well known becauste it is considered to be deficient in vegetarians. Due to its important functions, even if the intestinal microbiota manufactures it in a certain amount, it is better to ensure a good contribution through supplements, which can prevent avoidable complications.

Functions of Vitamin B12

mother with their children

Vitamin B12 or cobalamin is necessary for growth:©Dibujosparapintar

– For the formation of red blood cells.

– For the good health of brain cells and the nervous system, together with vitamin C and methionine.

– To defend against stress.

– To avoid discouragement and dismay.

– To get a good functioning of the mind.

– For the good health of the cells of the bones.

– For proper growth.

– For cell renewal, along with folic acid and other nutrients.

– For the absorption of vitamin A and iron.

– Along with folic acid, pantothenic acid, vitamin C and other vitamins, it is involved in the metabolism of fats and carbohydrates.

Functions of B12 for circulation: Homocysteine ​​Cycle

Vitamin B12 is needed to reduce levels of homocysteine, a very harmful amino acid because it damages the arteries. High levels of homocysteine ​​in the blood are related to the formation of the atheroma plaque that clogs the arteries.

Cobalamin improves circulation because it plays a very important role in the transformation of homocysteine ​​into methionine (homocysteine-methionine cycle). It collaborates with folic acid (Folic acid passes the methyl group to cobalamin, and cobalamin inactivates homocysteine).

Smokers have more homocysteine ​​in the blood and therefore worse circulation. For this reason they need higher requirements of methylcobalamin and folic acid.

Vitamin B12 in the body

Is there a vitamin B12 store?

Vitamin B12 is stored in a certain amount in the liver, from where the body takes it as needed. It is true that the liver is able to store small amounts of vitamin B12, in the form of adenosyl-cobalamin, but this is not insufficient.

store of vitamin B12

It is a widespread myth that there is a very large store of vitamin B12 and therefore it is not necessary for vegetarians to take it.

Where can you find vitamin B12?

Foods rich in animal proteins

Foods rich in animal proteins are the richest in cobalamin

Vitamin B12 can only be obtained from foods of animal origin. One of the richest foods are clams (Each gram of this seafood contains almost one mcg of cobalamin).

Viscera, such as the liver, brain, or kidneys, are the richest foods after clams (85 grams of beef liver contain 68 mcg, the same amount in chicken liver as 16.6 mcg)

Some fish, such as tuna, sardines, are quite rich, especially the small fish that is consumed with the fishbone.

Other foods with lower amounts are white meats, red meats and eggs. Milk and dairy products are often enriched in vitamin B12.

Vitamin B12 in vegetarian diet foods

Photo of tofu

Photo of tofu. Plant foods are NOT a good source of vitamin B12

Plant foods contain negligible amounts of this vitamin. It had been said that fermented products like tempeh or miso could contain a certain amount of B12. Also some algae contain vitamin B12.

All these sources are not good sources of B12 because firstly they are very rare in this component, and especially because it is a type of analogous vitamin B12, that is to say, without biological activity.

Foods fortified with vitamin B12

At the moment you can also find vegetable products enriched with this vitamin that could help to prevent its deficit (like vegetable drink enriched with: calcium, vitamin B and B12, for example).

* More information: Vitamin B12 rich food in the listing

Daily needs of vitamin B

The daily requirements for vitamin B12 are 2.5 mcg daily.

Vitamin B12 content of food per serving

Expressed in micrograms (mcg) of vitamin B12

125 gr cow liver81
5 sardines (300 gr)55
2 turkey breasts (350 gr)4
1 fillet of cod (220 gr)3
1 fillet of hake (200 gr)2
2 slices of cured cheese (60 gr)2
1 egg (60 gr)1,1
1 yogurt (125 gr)0,5
glass of milk (200 ml)0,5
90 gr egg pasta0,2

Deficits in vitamin B12

Symptoms of vitamin B12 deficiency

Symptoms that may indicate lack of vitamin B12. Deficiency in this vitamin leads to serious complications such as anemia.

Intrinsic factor for the absorption of vitamin B12

Vitamin B12 has a very peculiar absorption system, which requires the participation of the gastric juice of the stomach and a component called intrinsic factor.

Vitamin B12 is found in foods linked to proteins. In the stomach, gastric juices break down proteins and release the vitamin B12 contained in food. In addition to the gastric juices intrinsic factor is also secreted.

In the intestine, vitamin B12 is captured by the intrinsic factor (the alkaline medium of the intestine favors its binding) and subsequently this vitamin is absorbed. Without the intrinsic factor, that the stomach produces, B12 can not be absorbed.

B12 Deficiency due to stomach problems

The decrease in intrinsic factor or lack of gastric juices (atrophic gastritis, gastric hypoacidity or hypochlorhydria gastritis), something that usually occurs from the age of 50, is responsible for the decrease of this vitamin, which forces to maintain a special care not ot to fall into the diseases that can produce its deficiency.

Currently the deficiency of this vitamin occurs quite commonly in the elderly, affecting 40% of people over 80 years and 25% of those over 60 years.

Deficit can also occur if there are operations for obesity in which the stomach is partially resected (gastric sleeve surgery or bypass).

B12 supplements are recommended to vegetarians? YES


In pregnancy, vegetarian women should take supplements

It is very likely that a vegetarian diet will not provide the necessary amount to avoid deficiencies of this vitamin, especially when no dairy or eggs are consumed.

Official agencies recommend that vegetarians take cobalamin supplements because it is a very safe food supplement and can prevent many avoidable complications.

Given the controversy on this issue, we take the opportunity to recommend to vegetarians that if they have doubts they consult dietitians who are experts in vegetarianism or associations of dietitians in their country.

When are B12 supplements needed? Types of Vitamin B12 Supplements

Intake of vitamin B12 supplements may be necessary in special circumstances when diet may not meet individual needs. In these cases, the ingestion of vitamin B12 supplements is recommended.

Supplements are usually given in doses of 10, 100 or up to 200 mcg. Daily, every day or every other day.

Other products such as B12-enriched brewer’s yeast may be a good supplement, although it is safer to directly use a vitamin B12 supplement.

It is also possible to find vitamin B12 in multivitamin complexes, although its prolonged use is not recommended nor its administration if it is not recommended for a medical reason.

Vitamin B12 is better absorbed when calcium levels are adequate. It is advisable to take foods rich in this mineral to favor its absorption.

B12 during pregnany and lactation

Vegetarian women in pregnancy and lactation must take B12 supplements. B12 deficiency in infants is severe and may produce neurological sequelae. It has been proven to be a safe supplement to take in pregnancy.

How to supplement vitamin B12 in vegetarians?

It is not necessary to take supplements daily. Vegetarians can take vitamin B12 supplements daily or 2-3 times a week. Special vegetarian supplement brands offer doses of up to 1,000 mcg (for 1-2 weekly doses ** this dose is contraindicated in pregnant women) or 100-200 mcg (daily dose or for every 2 days).

Supplementation guidelines may vary depending on the expert’s criteria, age, and health conditions of the individual.

Scheme of the recommended dose of vitamin B12

Scheme of the recommended dose of vitamin B12 in supplements, for healthy adults.

It is always recommended to go to a dietitian expert in vegetarianism to avoid possible nutritional deficits other than vitamin B12. (Please inform yourself in your country’s dietitian associations).

Special daily vitamin B12 needs

The recommended daily amount of vitamin B12 increases in certain situations:

Elderly or people over 50: The low production of intrinsic factor, or heartburn may be responsible for poor absorption of this vitamin from the 50’s.

Pregnancy or breastfeeding: Cobalamin is absorbed in part by the fetus or baby and the mother needs additional ingestion. If little food of animal origin is consumed or the mother is a vegetarian, it MUST be supplemented.

Medications against stomach acidity, gout, epilepsy, or potassium supplements.

People who routinely take laxatives.

Smokers: Tobacco is responsible for poor absorption of the B vitamins.

Strict vegetarian diet. Vegetarians can take a few years to notice this deficiency because the body takes the amount it needs from liver stores.

People who eat a lot of sweets or fats, since sweets alter the fermentative intestinal flora necessary to produce and absorb this vitamin.

Intestinal diseases: People with frequent diarrhea such as Crohn’s disease or ulcerative colitis.

Stomach surgeries, after which it is usual for the organism to produce little intrinsic factor.

Problems caused by lack of cobalamin


Cobalamin deficiency can be a cause of learning and fatigue problems

A deficiency of this vitamin manifests itself mainly in the form of:

– Anemia

– Growth problems

– Tiredness, despondency, discouragement

– Problems of memory and learning.

– Nervous problems: By degeneration of myelin sheaths. Cobalamin deficiencies may manifest as alterations of the nervous system, such as nervousness, irritability, anxiety, depression, insomnia, etc.

– Tendency to suffer from infections

– Greenish skin tone

– Suspected degenerative diseases, such as multiple sclerosis or osteoporosis.

– Suspicion of mental problems, such as schizophrenia.

* Related information:

Symptoms of vitamin B12 Deficiency

Diagnostic of vitamin B12 deficiency

Vitamin B12 supplements

Vitamin B12 supplements for vegetarians

Vitamin B12 analogues

How to take vitamin b12 supplements

Deficiency of vitamin b12 in babies or vegetarian children

Vitamin B12 during pregnancy

Does the body store vitamin b12?

punto rojoMore information on vitamin b12.

Written by Editorial Botanical-online team in charge of content writing

11 December, 2019

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