Vitamin B12 (cobalamin)

Vitamin B12: What is it important for?

The water-soluble vitamin B12 plays an important role in many endogenous processes. For example, it protects nerve fibers in the spinal cord and plays a key role in cell growth and cell division. In addition, vitamin B12 is needed for blood formation. Since it converts the amino acid homocysteine, which is harmful to the heart and circulation, into harmless methionine, vitamin B12 is also thought to have a preventive effect against vascular diseases such as arteriosclerosis.

How does vitamin B12 get into the body?

Vitamin B12 cannot be produced by the human body itself. It must therefore be supplied through the diet. The daily requirement for healthy adolescents and adults is around 3 micrograms, and for young children it is 1.5 micrograms. However, there are recent studies that show a requirement of 7-10 micrograms for adults. Pregnant women also have a significantly higher daily requirement.

The daily amount of vitamin B12 required by the body of a healthy adult can be met, for example, by consuming one of the foods listed below:

100 gram beef
100 gram salmon
3 eggs
2 slices of Emmental cheese (40 grams)
500 milliliters whole milk

To ensure a sufficient supply of vitamin B12, fish should be on the menu one or two days a week, and it is also advisable to have an egg for breakfast now and then. Furthermore, the moderate consumption of meat and the intake of dairy products are very advisable.

What happens with a vitamin B12 deficiency?

In Central Europe, vitamin B12 deficiency is relatively rare. However, since vitamin B12 is found exclusively in animal foods, it is very difficult for vegetarians and almost never for vegans to cover their daily requirements through their diet. People with certain intestinal diseases such as Crohn's disease can also develop a deficiency. In addition, there are various drugs that inhibit the formation of gastric acid (so-called proton pump inhibitors).

B12 deficiency generally leads to megaloblastic-hyperchromic anemia, anemia associated with pallor and frequent fatigue. Furthermore, numbness, dizziness, gastrointestinal problems or burning of the tongue may indicate a deficiency. If such symptoms occur, a visit to the doctor is urgently recommended.

What are the consequences of vitamin B12 overdose?

Since vitamin B12 is water-soluble and is excreted by the kidneys in the case of increased intake, an overdose generally has no consequences. However, allergic reactions may occur in the case of intravenous supply, but these are only localized and are usually of short duration. Despite this relatively low risk of overdose, dietary supplements with vitamin B12 are only advisable in a few cases. On medical recommendation, however, they can be quite useful for people with symptoms of undersupply.