Everything you should know about vitamin B12 if you are vegan (or strict vegetarian)


Everything you should know about vitamin B12 if you are vegan (or strict vegetarian)

Vitamin B12 is essential for vegans or strict vegetarians since it is a vitamin that we find especially in foods of animal origin. Discover everything you need to know about it.

Did you know that a relatively low intake of vitamin B12 can cause a deterioration of the nervous system and also anemia? It is what is medically known as vitamin B12 deficiency, and the main reason is due to the reduced or no intake of foods rich in this vitamin.



Vitamin B12 is an essential nutrient also known as cobalamin. It is a recently discovered vitamin since its structure was discovered in 1956 as a result of a study of medical and scientific research on pernicious anemia.

Veganos y vitamina B12

In fact, as many specialists say, it is possible that when there is a deficit of vitamin B12 the symptoms of pernicious anemia are hidden if enough folic acid is consumed until it is too late and irreversible neurological damage has already occurred.

What are the functions of vitamin B12?
Among other important functions, vitamin B12 is essential for:

The nervous system maintains a healthy nervous system, maintaining the myelin sheath that protects and surrounds the nerves.
For growth: it is essential for children since it promotes growth.
For red blood cells: it is necessary for the production of red blood cells in the blood (hence, its deficit produces anemia).
For metabolism: it is used by our body to metabolize fatty acids.
And what are the consequences of its deficit?
A deficit of vitamin B12 can pose a risk to health, and cause certain disorders or conditions. In the case of many strict vegetarians or vegans, the risk comes from not recognizing the seriousness of the consequences of vitamin B12 deficiency. We summarize those consequences below.

Vitamin B12 deficiency anemia is a condition in which our body does not have enough red blood cells. Symptoms may be mild and include symptoms such as inappetence, fatigue, dizziness when standing or making an effort, concentration problems, pale skin, lack of appetite, diarrhea or constipation and difficulty breathing.


The risk is higher if low levels of vitamin B12 are maintained over time since neurological damage can occur, which we will discuss below.

Neurological damage
This damage is associated with vitamin B12 deficiency, especially when this deficiency is maintained over time. Among other associated symptoms, it can be confusion, dementia (especially in severe cases), loss of balance, numbness, and tingling of the hands and feet, and depression.

Other associated conditions
In addition to the two health conditions listed above, other problems may also occur, such as:

A potential risk of heart disease.
Complications in pregnancy.
Menstrual problems

Síntomas déficit B12 en veganos

Why is your extra consumption so important by strict vegans and vegetarians?
Unless large amounts of breakfast cereals are enriched with this vitamin, the most common is that both vegans and strict vegetarians are deficient in vitamin B12 if they do not consume an extra vitamin B12 supplement. Why? Fundamentally because it is only obtained from products of animal origin.

In this sense, many argue that some foods of plant origin, as for example is the case of some seaweed (especially spirulina or nori), some mushrooms (such as chanterelle or shiitake) or products of tempeh and provide vitamin B12 But the truth is that they contain amounts not always bioavailable and in such controversial amounts that it would be a risk not to supplement the diet with nutritional supplements that do.

Put another way, the only reliable sources of vitamin B12 that are also vegan are foods enriched with it. And is that although many vegans or strict vegetarians consume sufficient amounts of this vitamin to prevent the deterioration of the nervous system or pernicious anemia, the reality is that they do not obtain the necessary amount to minimize the risk of complications in pregnancy or heart disease.


The risk is even greater if we take into account that in order to detect the organic consequences of this deficit and the lack of this vitamin, it can take years.

But if you are ovolactovegetarian you can be calm, since when consuming foods of animal origin like eggs, cheese or milk, you will obtain sufficient amounts of vitamin B12. For example, Brie cheese is one of the richest animal foods, contributing around 3.10 mcg.

How to provide enough vitamin B12 to your body if you are vegan?
As the Vegan Society itself (an association founded in 1944 with the aim of spreading the vegan adopting a recognized approach for the reduction of animal consumption and suffering), to follow a vegan or strict vegetarian diet with some tranquility, it is important that some of the following points:

Consume 2 or 3 times a day foods fortified with vitamin B12 (at least 3 mcg or ug).
Take a vitamin B12 supplement a day that provides 10 mcg.
Take a vitamin B12 supplement a week that provides 2000 mcg.
If you opt for the consumption of fortified foods it is very important to carefully check the label of the food, to make sure that you are effectively getting enough B12. Let’s take an example: if you choose to consume a bowl of enriched cereals with enriched vegetable milk that together gives you 1 mcg of B12 per serving, then you will get an adequate contribution if you consume 3 servings a day.

  Disclaimer: All content on this website is for informational purposes only and should not be considered to be a specific diagnosis or treatment plan for any individual situation. Use of this website and the information contained herein does not create a doctor-patient relationship. Always consult with your own doctor in connection with any questions or issues you may have regarding your own health or the health of others.