Vitamin B12, also known as cobalamin, is a B vitamin, which means it is soluble in water.
It is a very important vitamin for the functioning of the brain, nervous system and DNA synthesis.
This vitamin must be obtained from food, and the populations most at risk of deficiency are vegans and the elderly due to their low consumption of animal foods.
Characteristics of vitamin B12
- Found in animal products
- Essential for the health of the nervous system
- Its deficiency can cause anaemia
- Necessary supplementation in vegan diets
What is vitamin B12 used for?
Role in haematopoiesis
Vitamin B12 has an anti-anemic role and also helps in the assimilation of folic acid (vitamin B9).
Maintenance of the nervous system
Vitamin B12 is particularly important at the level of the myelin sheath, where it helps to protect nerve cells.
Anti-allergic function
Combined with an antihistamine, vitamin B12 can play a beneficial role in relieving allergic symptoms.
It also has a detoxifying effect, helping the body to rid itself of toxins accumulated in the liver.
Vitamin B12 and cancer
To date, some scientific studies have highlighted the detoxifying role of vitamin B12 after certain types of chemotherapy.
Where is vitamin B12 found?
Vitamin B12 is mainly found in foods of animal origin, as animal foods are themselves fortified with B12.
No animal or plant can synthesise B12, only certain bacteria can.
Here are 19 foods that contain good amounts of vitamin B12.
Foods - Portions - Amount of vitamin B12 (μg)
- Beef liver - 100g = 65
- Veal liver - 100g = 60
- Lamb liver - 100g = 35
- Caviar - 100g = 16
- Oysters - 100g = 14,5
- Liver pâté - 100g = 13,5
- Rabbit - 100g = 10
- Liver dumplings - 100g = 10
- Mackerel - 100g = 9
- Herring - 100g = 8,5
- Mussel - 100g = 8,5
- Meat - 100g = 5
- Wild boar - 100g = 5
- Trout - 100g = 4,5
- Tuna fish - 100g = 4.3
- Goose - 100g = 4
- Wild salmon - 100g = 3.5
- Camembert cheese - 100g = 3.1
- Emmental cheese - 100g = 3.1
How should vitamin B12 be used?
ANSES recommends a daily intake of 2.4 μg of vitamin B12 for a healthy adult.
Vitamin B12 supplementation in a vegan diet
Vitamin B12 supplements are recommended for people who follow a vegan diet or who consume very little food of animal origin.
Whatever the form (tablet, ampoule, injection, etc.), vitamin B12 is absorbed by the body in the same way.
When vitamin B12 is taken in the form of a food supplement, the dose can be as high as 5000 μg, which is far from the recommended daily dose of 2.4 μg.
This is because vitamin B12 is stored in the body, so certain supplements can be taken monthly rather than daily.
At the same time, vitamin B12 in a pill is not fully absorbed by the body, so you need to take a very high dose supplement to cover your needs.
To find out which vitamin B12 is right for you, ask your doctor.
In some cases, vitamin B12 can be given by injection.
For example, in cases of severe malabsorption or after digestive surgery.
However, vitamin B12 injections can cause some undesirable side effects: itching, hives, eczema, etc.
Vitamin B12 deficiency
Many symptoms can occur with vitamin B12 deficiency, the most common being neurological symptoms (tingling, pain), anaemia (low levels of iron in the blood) and digestive disorders (constipation, diarrhoea).
Vitamin B12 deficiency can also lead to more general symptoms such as hair loss, pallor, etc.
If in doubt, consult your doctor.
He or she will be able to explain how to treat a vitamin B12 deficiency, if necessary and according to your case.
If I have too much vitamin B12 in my blood, what are the symptoms?
It is very rare for too much vitamin B12 to enter the body. So far, the only side effect of excessive B12 intake has been acne, and no real toxicity has been demonstrated.
Interactions of vitamin B12 with other elements
Many nutrients have a positive effect on vitamin B12 metabolism and vice versa.
For example, vitamin B9 needs vitamin B12 to be activated, so a vitamin B12 deficiency often results in a concomitant vitamin B9 deficiency.
Vitamin B12 also needs vitamin B7 and magnesium to be bioactivated.
Finally, vitamin B2 and vitamin B3 and calcium are essential for vitamin B12 metabolism.
It may be advisable to take a multivitamin in addition to vitamin B12 and in the event of a deficiency.
Chemical properties
Vitamin B12 or cobalamin is a water-soluble B-complex vitamin.
Its chemical formula is C72H100CoN18O17P and its molecular weight is 1579.5818 g/mol.
This vitamin is directly involved in the proper functioning of the nervous system and the production of DNA.
Vitamin B12 exists in 8 different forms, all of which are derived from cobalamin.
Cobalamin is similar in structure to haem.
However, the central iron atom is replaced by a cobalt atom.