Comprendre la carence en vitamine B12 (Causes, Symptômes, traitement)

Understanding Vitamin B12 Deficiency (Causes, Symptoms, Treatment)

In this article, we will come back to the causes of vitamin B12 deficiency, the symptoms that accompany it and the means of treating it.
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Vitamin B12, or cobalamin, is an essential vitamin for the proper growth and maintenance of the body.

In its natural state , vitamin B12 is only produced by certain bacteria present mainly in soils and which accumulate in herbivorous animals. The vast majority of vitamin B12 in the food chain comes from the consumption of these animals.

Vegan consumers, vegans, vegetarians, and those who have significantly reduced their consumption of foods of animal origin (flexitarians) or whose assimilation is limited are directly affected by a risk of vitamin B12 deficiency. The synthesis of vitamin B12 in the laboratory was a decisive turning point in securing plant-based diets less than 50 years ago.

In this article, we will look at the causes of deficiencies, the symptoms that accompany them and the ways to treat them.

Causes of vitamin B12 deficiency

The deficiency (hypovitaminosis B12) is often associated with insufficient consumption of animal proteins and a lack of corrective supplementation with suitable food supplements.

There are in reality many other factors which influence the assimilation of vitamin B12 and can induce deficiencies even with satisfactory theoretical intakes:

Treatments and taking medications

Certain medications have a negative impact, often varying from one individual to another. This is the case for metformin prescribed as a basic treatment for Type 2 diabetes. It is regrettable that, with some exceptions, these risks are never explicitly described in the legal notices. It is always prudent to ask the pharmacist about this.

Limited assimilation (age, intrinsic factor, diseases)

  • Age :

Concurring statistical studies show that a significant proportion of elderly people have a vitamin B12 deficiency: 10 to 20% from the age of 50 and this percentage increases with age.

The main cause is the drop in stomach acid which disrupts the process of converting vitamin B12 in the body .

  • Disease :

Specific pathologies identified as Biermer disease (or Biermer anemia) causing so-called “pernicious” anemia.
In this case, the deficiency results from a lack of secretion of a specific molecule called intrinsic factor, essential for the transport of vitamin B12 in the intestine and its passage into the blood. The percentage of vitamin B12 assimilated is directly linked to the quantity of intrinsic factor available.

Population categories with increased needs

For safety reasons, pregnant women and athletes are considered to have increased daily needs for vitamin B12.

For young people, any lack of vitamin B12 can have a direct impact on growth and proper development. These situations require special attention to covering daily intakes of vitamin B12.

A general situation to monitor for everyone

Vegans and vegetarians are increasingly better informed about the mandatory nature of taking vitamin B12 supplements.

This awareness does not exist among omnivores while a significant proportion (of the order of 20%) have structurally insufficient vitamin B12 intakes, linked to meat foods with a low B12 content.

The paradox could soon be to observe more deficiencies among omnivores than among vegans!

vitamin B12 deficiency cause treatment argalys 1

Symptoms of vitamin B12 deficiency

Structural vitamin B12 deficiency has effects that may be irreversible:

  • In a relatively short term for growing subjects (from the fetal stage) since it directly impacts the proper development of the body and in particular of nervous tissues.
  • Much less noticeable when growth is complete, which is also dangerous (accelerated aging of nervous tissues, etc.).

It is not easy to diagnose vitamin B12 deficiency , especially since it is mild because it presents symptoms similar to other pathologies.
The best thing is to ensure satisfactory daily intakes, if necessary by having them assessed by a professional (nutritionist, dietitian).

The symptoms fall into 2 main categories:

  1. Anemia
  2. Neurological disorders

Anemia due to vitamin B12 deficiency (intake or assimilation)

Vitamin B12 deficiency can lead to anemia .

This results in a decrease in the hemoglobin level (below its threshold value) due to lack of red blood cell production.

Oxygen is then less well transported in the blood and the symptoms observed are those of all types of anemia: tingling, numbness of the feet and hands are among the first felt, then fatigue, general weakness, shortness of breath, dizziness.

The multiplicity of possible causes makes it difficult to identify a lack of vitamin B12 with these symptoms alone.

As mentioned above, vitamin B12 deficiency results in:

  • Or insufficient intake: which is easily corrected through nutrition and food supplements.
  • Either assimilation defects: resulting from specific pathologies which disrupt the action of the intrinsic factor necessary for assimilation such as Biermer's disease. Anemia is called “pernicious” because it develops despite sufficient vitamin B12 intake.

Neurological disorders linked to vitamin B12 deficiency

Vitamin B12 is directly involved in the development and regeneration of nervous tissues.

Consequently, its deficiency leads to degradation of the protective sheaths of neurons (myelin).

Repeated tingling in the extremities of the limbs are the first frequent and warning effects of a possible B12 deficiency (but not specific). It is therefore preferable to consult a professional as soon as symptoms appear.

In fetuses and children, vitamin B12 deficiency is even more harmful because it disrupts brain development. This can cause irreparable effects.

Other disease risks

In addition to the risks mentioned above, a vitamin B12 deficiency exposes you to more:

  • Cardiovascular diseases (Humphrey et al., 2008)
  • Alzheimer's disease (Nourhashemi et al., 2000; Selhub et al., 2000),
  • Cervical cancer (Myung et al. 2011)
  • Birth defects (in babies of deficient mothers)
  • Bone weakening.

How to prevent or treat vitamin b12 deficiency

In the majority of cases, vitamin B12 deficiency does not cause any irremediable damage when it is detected early enough in subjects who have completed their growth.

To treat a deficiency, two methods exist depending on the degree of urgency to correct the problem and/or its origin.

  1. Oral vitamin B12 supplementation
  2. Vitamin B12 administered by injection.

Taking a food supplement rich in vitamin B12

The simplest solution to avoid deficiencies : taking a food supplement!

For the vast majority of diets presenting a risk of vitamin B12 deficiency, regular intake of vitamin B12 in food supplements is the simplest way to prevent risks without too many daily constraints and at a moderate cost.

It also allows, with the taking of larger doses over several weeks or months, to bring the vitamin B12 level back to a correct level.

It is important to point out that there is no risk of overdosing on vitamin B12. It is a vitamin that is very soluble in water. Also, excess quantities are easily eliminated in the urine, without kidney fatigue because the quantities remain tiny: a few tens of micrograms.

Supplementation must be dosed: the quantity of vitamin B12 provided must be clearly measured and adapted to the frequency of intake (daily, twice weekly, weekly).

The supplementation reference values ​​for an adult are:

  • Omnivores: 2.5 micrograms/day (the official NRV level)

Majority plant diets:

  • Per daily intake: 5 Micrograms/day
  • Per weekly dose: 1 milligram
  • Strict vegan diets: 10 micrograms/day or 1 milligram (mg) twice a week

Regular taking of vitamin B12 supplements is obligatory for vegan (or vegetarian) consumers, with, remember, particular attention to pregnant women and their babies and growing young people.

Note that with age, the assimilation of vitamin B12 decreases. Thus, omnivorous seniors will be advised to prevent any risk by switching to taking a supplement dosed at 1 mg, taken weekly.

Vitamin B12 injection

Intravenous injection is obviously a practice strictly related to medicine and therefore in particular and serious situations.

We use it:

  • Or to correct as quickly as possible the effects of a critical deficiency, particularly with nerve damage (when they are not irreversible).
  • Either to compensate for poor absorption in cases of pernicious anemia, stomach surgery which disrupts the production of intrinsic factor or long-term drug treatment (Metformin/T2 diabetes for example)

In the first case, daily or weekly injections are prescribed for a period allowing a return to normal. In the second case, the treatment will be long-term.

Our food supplements rich in vitamin B12

The Argalys Essentials range has been designed to facilitate the balance of modern diets for everyone.
It is therefore very logical that we have paid particular attention to vitamin B12.

Three solutions are proposed:

  • For daily intake: the Multivitamins and Minerals provides 10 micrograms of B12 per capsule (400% VNR): a very safe daily dose, associated with a broad spectrum of vitamins and Minerals (D3, Iodine, Zinc etc.)
  • For weekly intake by seniors, flexitarians or twice a week (vegans): the Vitamin B12 + Iodine and Selenium formula contains 1000µg (1 mg) of vitamin B12 per capsule, it is the most economical solution on the market with an unrivaled quality/price ratio .
  • From 1 year old: the new Vegakid (released April 2021): a new formula adapted to the youngest, with adapted contributions of vitamin B12 but also: Vitamins D3 and E, Calcium, Iodine, zinc and Selenium.

The role and importance of Vitamin B12 are becoming better and better known. The popularity of diets with less or no animal protein further increases the usefulness of vitamin B12 supplements.

If in doubt, do not hesitate to have your intake and that of your children assessed by a nutrition professional, it is a very reasonable precaution.


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