Vitamin B12: Function & Diseases

Vitamin B12 belongs to the vitamin B series. It is water-soluble and influences fundamental processes in the body. Especially in metabolism, vitamin B12 has tasks that cannot be replaced.

Mode of action of vitamin B12

Foods such as meat and eggs or milk are particularly rich in vitamin B12. Vegetarians therefore do not have to fear an undersupply, since they take in enough vitamin B12 via eggs and dairy products.

A deficiency of vitamin B12 is most noticeable when anemia develops. Among other things, vitamin B12 is responsible for the formation of red blood cells. These in turn ensure the transport of oxygen in the body.

In addition, vitamin B12 is involved in cell division and the formation of new cells. Vitamin B12 is essential for the formation of DNA, the genetic material. It is also necessary for the formation of the protective sheath around the nerve fibers.

Finally, vitamin B12 enables the absorption of folic acid into human cells. The transport medium for vitamin B12 is the intrinsic factor (IF). This is found in gastric juice and transports vitamin B12 into the human blood.

Importance

A deficiency of vitamin B12 often becomes apparent very late in life because the body can store stores of this vitamin in the liver for several years. One of the most common manifestations of vitamin B12 deficiency is so-called pernicious anemia (anemia due to vitamin B12 deficiency).

The first symptoms here are increasing general weakness, difficulty concentrating or shortness of breath. Particularly during sporting activities, those affected notice that they are no longer able to work at full capacity. In the most extreme case, a chronic fatigue syndrome develops.

A lack of vitamin B12 is also noticeable in an increased susceptibility to infections, a pale complexion and white lips. The reduced oxygen transport rate of the red blood cells also leads to memory weakness, and under certain circumstances a deficiency can even lead to the suspicion of Alzheimer’s disease.

But also in depressed persons and with increasing nerve pain or sensory disturbances in hands and feet, the vitamin B12 level should be absolutely controlled.

Only recently has it been discovered that older people in particular are increasingly affected by vitamin B12 deficiency disease. Due to age-related changes, the stomach produces less gastric juice.

This in turn reduces the formation of intrinsic factor and the ability to absorb vitamin B12 is reduced. Here it is important to determine the concentration of vitamin B12 in the central nervous system if dementia and the like are suspected.

In addition, vitamin B12 deficiency also plays a role in widespread diabetes or even multiple sclerosis. Likewise, vitamin B12 is additionally administered in psychiatric delusional disorders. Not yet proven – though research is already in full swing – is the involvement of a vitamin B12 deficiency in the development of coronary artery disease.

Occurrence in food

Normally, the daily diet is sufficient to cover the need for vitamin B12. Abundant vitamin B12 is found in almost all animal foods of animal origin.

Particularly rich in vitamin B12 are foods such as meat (here especially the liver) and eggs or milk. Vegetarians therefore do not have to fear an undersupply, as they take in sufficient vitamin B12 via eggs and dairy products.

However, those who do without all animal products take up virtually no vitamin B12 through their diet. In this case, vitamin B12 must be supplied via a vitamin preparation. Pregnant and breastfeeding women have an increased need for vitamin B12. This group of people is routinely prescribed vitamin preparations to prevent an undersupply at an early stage.