Vitamin B12 and vegan nutrition: What is really important?
Vitamin B12 is a particularly critical nutrient in a vegan diet. It is often claimed that people can ingest it through unwashed plants or natural soil bacteria. This is not a reliable supply strategy. This article explains where vitamin B12 comes from and how to ensure a safe supply.
Where does vitamin B12 come from?
Vitamin B12 is produced exclusively by certain microorganisms. Plants and animals do not produce the vitamin themselves. Animals can absorb it through microorganisms in their digestive systems or through food; This allows it to accumulate in animal foods.
The fact that bacteria produce vitamin B12 in soil or water does not mean that unwashed plants are a safe source for humans. The amount and bioavailability are unpredictable. Fermented foods, algae and other plant-based products are also not reliable sources of biologically active vitamin B12.
Why is vitamin B12 critical in a vegan diet?
Vitamin B12 occurs naturally in sufficient and reliably available quantities, especially in animal foods. These foods are completely missing from a vegan diet. That's why vegans need a reliable source of fortified foods and, in particular, a suitable vitamin B12 preparation.
Even vegetarians can be inadequately nourished if they only eat small amounts of dairy products or eggs. Occasional consumption of fortified products does not automatically guarantee adequate supply.
How much should be supplemented?
The daily reference value describes the requirement, not directly the required supplement dose. In the case of preparations, the limited absorption via the intrinsic factor and the additional passive absorption at higher individual doses play a role. Supplement doses cannot therefore simply be equated with daily requirements.
There are different dosage regimens, such as regular daily or higher doses weekly. The appropriate dose depends on the preparation, how frequently it is taken, individual factors and previous supply status. The DGE recommends that vegans take long-term vitamin B12 supplements and regularly monitor their supply.
How can supply be checked?
In addition to serum vitamin B12, depending on the situation, holotranscobalamin (Holo-TC), methylmalonic acid (MMA) and, if necessary, homocysteine can be helpful. A single laboratory value is not always sufficient to reliably assess the supply status. The selection of examinations should be classified medically.
Reliable care is particularly important during pregnancy and breastfeeding as well as in infancy and childhood. A prolonged deficiency can affect blood formation and the nervous system.
Do omnivorous humans also need B12?
People who eat animal foods can also develop a vitamin B12 deficiency. Reasons include, for example, impaired absorption in the gastrointestinal tract, certain medications, older age or a very low intake. An omnivorous diet therefore does not automatically guarantee good nutrition.
A multivitamin preparation is not generally necessary for all vegans. It is crucial to plan critical nutrients specifically. Vitamin B12 is indispensable; Other nutrients should be assessed based on diet and individual living situation.
Conclusion
Vitamin B12 is produced by microorganisms and cannot be reliably obtained from unprocessed plant-based foods on a vegan diet. Long-term, reliable supplementation is therefore necessary. Regular checks and a suitable intake strategy help to avoid deficiency states. You should not rely on soil, unwashed vegetables or seaweed as a source of vitamin B12.