Vitamin B12: What it is and how it benefits your health

Vitamin B12, also known as cobalamin, is essential for many vital functions in your body. It supports your nervous system, ensures the formation of red blood cells and plays a key role in cell division. Because of its strong colour, it is also called the ‘red vitamin’. However, your body cannot produce it itself, so you must obtain it through your diet or supplements.

Without enough vitamin B12, your body would produce fewer red blood cells, which can lead to anaemia, causing symptoms such as numbness, tingling and muscle weakness. But B12 can do even more! It supports cell division and ensures that your central nervous system runs smoothly. Long-term B12 deficiency can lead to depression, confusion and impaired brain function.

Together with other nutrients, B12 also helps to keep your homocysteine levels in balance to support your cardiovascular health.

If you are deficient in B12, your body may have difficulty providing enough energy, which can lead to fatigue, exhaustion and concentration problems. B12 also helps the body detoxify harmful substances.

Vitamin B12 is found almost exclusively in animal-based foods such as meat, fish, eggs and dairy products. If you follow a vegan or vegetarian diet, you may quickly become deficient in this vitamin, as it is virtually absent from plant-based foods. It is therefore important to ensure you have an adequate supply to prevent vitamin B12 deficiency!

Offal is particularly rich in vitamin B12, with duck meat and various types of liver being among the best sources. Seafood such as oysters, mussels and fatty fish such as herring and mackerel also provide significant amounts. Among meat types, rabbit, wild boar and lamb also contribute to the supply. Among dairy products, strong cheeses such as Emmental, Camembert and Gouda stand out, while eggs and fermented milk products such as yoghurt can also contribute.

You can find detailed information in the vitamin B12-rich foods table in the appendix.

Plant-based foods with vitamin B12? They exist – but only in tiny amounts! Fermented products such as sauerkraut or beer and unwashed root vegetables may contain traces of it. Sounds good? Unfortunately, there's a catch: these are often so-called B12 analogues, which your body cannot utilise — and which can even block the absorption of real vitamin B12. That's why it's important to rely on reliable sources of B12!

In order for our body to utilise vitamin B12, it must first be released from food. It then binds to a special protein, the intrinsic factor, which is produced in the stomach lining. Only then can vitamin B12 be actively absorbed in the small intestine.

The good news is that in higher doses, e.g. through supplements (vitamin B12 tablets, capsules or drops), the body can also absorb vitamin B12 passively through the intestinal mucosa.

Fortunately, our bodies don't need much vitamin B12 – according to the German Nutrition Society (DGE), 4 µg per day is enough to maintain balance. However, there is one exception: during pregnancy and breastfeeding, the requirement increases to 4.5 and 5.5 µg per day, respectively. Conveniently, our bodies even have B12 stores and can accumulate reserves – in the best case up to 4 g, which is a thousand times the daily requirement! But be careful: a prolonged deficiency can gradually deplete these stores.

To improve absorption, it is helpful to take vitamin B12 on an empty stomach or between meals.

When you have your vitamin B12 status checked, the total vitamin B12 in your blood is usually measured. This sounds reasonable, but there is a catch: this value often only indicates a deficiency at a late stage. This means that even if it is normal, your supply may already be critical.

Better? The holotranscobalamin value (Holo-TC) – also known as ‘active B12’. It provides early indications of a negative B12 balance and empty stores. Methylmalonic acid (MMA) in the blood or urine is also a good indicator: if it is elevated, your body may already be suffering from B12 deficiency. So if you want to be sure, it's worth keeping an eye on these values!

Vitamin B12 and folic acid are real team players! They work hand in hand in metabolism and play an important role in homocysteine metabolism and blood formation*. But that's not all – these two B vitamins also support normal mental function and ensure that we stay mentally fit.

* Vitamin B12 plays an important role in normal red blood cell formation; folic acid contributes to normal blood formation.

Conclusion: Vitamin B12 is essential for many important bodily functions! Vegans, vegetarians, pregnant women, breastfeeding mothers, older people and those with gastrointestinal problems should pay particular attention to their intake. Regular B12 checks and targeted supplementation – through diet or supplements – will help you prevent deficiencies and keep your body fit!