What is vitamin B12?
Vitamin B12 is one of the B vitamins. Cobalamin, as it is also called, must be actively transported through the mucosal cells in the intestine into the body. A special protein, the so-called intrinsic factor, is necessary for vitamin B12 absorption. It is produced by the stomach mucosa and enters the intestine together with the food pulp.
The body can store vitamin B12 for several years, mainly in the liver.
One name for several compounds
The term vitamin B12 does not stand for a single chemical substance, but for several compounds with the same biological effect. These cobalamins are produced exclusively by bacteria (and blue-green algae). They accumulate naturally in animal products (such as liver, meat, eggs, dairy products). In addition, vitamin B12 is found in microbially produced foods such as sauerkraut.
What are the functions of vitamin B12 in the body?
Vitamin B12 influences a whole lot of important processes in the body. Particularly worth mentioning is the vitamin B12 effect for:
- cell division and differentiation, for example in the formation and maturation of red blood cells
- many reactions in protein and nucleic acid metabolism
Some celebrities swear by vitamin 12 for another reason – losing weight. Injected in high concentration, it is supposed to boost the metabolism. However, it has not been scientifically proven that this actually causes the pounds to fall.
Vitamin B12: Daily requirement
How much vitamin B12 one needs daily varies from person to person. For example, the daily intake recommended by the German Nutrition Society (DGE) depends on age. Pregnancy and breastfeeding also influence the vitamin B12 requirement.
According to the DGE, this is how much vitamin B12 you should take in:
|
Age |
Vitamin B12 |
|
µg/day |
|
|
Infants |
|
|
0 to under 4 months |
0,5 |
|
4 to under 12 months |
1,4 |
|
Children |
|
|
1 to under 4 years |
1,5 |
|
4 to under 7 years |
2,0 |
|
7 to under 10 years |
2,5 |
|
10 to under 13 years |
3,5 |
|
13 to under 15 years |
4,0 |
|
Adolescents and adults |
|
|
15 to under 19 years |
4,0 |
|
19 to under 25 years |
4,0 |
|
25 to under 51 years |
4,0 |
|
51 to under 65 years |
4,0 |
|
65 years and older |
4,0 |
|
Pregnant |
4,5 |
|
Breastfeeding |
5,5 |
Vitamin B12: Foods with high content
More about vitamin B12 levels in meat, fish, dairy products
How a vitamin B12 deficiency develops and what consequences it can have, you can read in the article Vitamin B12 Deficiency.
How does a vitamin B12 overdose manifest itself?
Too much vitamin B12 can hardly be absorbed, because the body does not absorb unneeded amounts through the intestinal wall. In addition, if the vitamin B12 dosage is too high, the excess can be excreted by the kidneys.
However, an overdose of vitamin B12 is possible with:
- liver metastases
- acute or chronic liver inflammation (hepatitis)
- excessive supply of vitamin B12 by the doctor (e.g. as an injection)
- leukemia
- polycythaemia vera (abnormal proliferation of mainly red blood cells, but also white blood cells)
Normally, vitamin B12 from food has no side effects. Vitamin B12 intake in the form of injections or infusions, however, can cause allergic shock in rare cases. In case of hypersensitivity, side effects occur very rarely even with external application (e.g. eczema or hives).
