Vitamin B12
Vitamin B12 plays a central role in longevity and healthy aging, even though it is often underestimated. The vitamin is essential for fundamental biological processes that determine how well our cells age, how stable our DNA remains, and how efficiently our bodies and minds function.
What is vitamin B12 important for?
Vitamin B12 is a key vitamin for many vital processes. It supports the formation of red blood cells, ensuring that our blood can transport sufficient oxygen. At the same time, it is essential for healthy nerves because it is involved in the formation of the protective sheath (myelin layer) that insulates nerve fibers. B12 also plays an important role in DNA synthesis and repair, i.e., in processes that determine how our cells renew themselves. A vitamin B12 deficiency can also increase homocysteine levels in the blood, which increases the risk of cardiovascular disease.
How much vitamin B12 do I need?
he daily requirement is around 4 micrograms. This is a very small amount, but without it, significant problems can arise in the long term, ranging from anemia to neurological disorders.
How can I meet my daily vitamin B12 requirement?
Vitamin B12 is found almost exclusively in animal-based foods such as meat, fish, eggs, and dairy products. People who follow a vegetarian diet can often still meet their needs through dairy products and eggs. However, supplementation is essential for vegans, as plant-based foods contain virtually no usable B12. Supplements are available in the form of tablets, drops, or sprays, all of which are effective. Regular intake is particularly important, as although the body can store B12, these reserves will eventually be depleted.
How can I recognize a vitamin B12 deficiency?
Vitamin B12 deficiency can manifest itself in many different ways—from mild fatigue to severe neurological symptoms.
Possible Symptoms:
General signs
- Fatigue, exhaustion, concentration problems
- Pale or slightly yellowish skin
- Shortness of breath, palpitations
- Dizziness or headaches
Neurological/psychological symptoms
- Tingling or numbness in the hands and feet
- Unsteadiness or muscle weakness
- Memory problems, irritability, depressive mood
- Rarely in severe cases: coordination and balance disorders
Digestive problems
- Loss of appetite
- Nausea
- Flatulence
- Burning tongue or smooth, reddened tongue
How do I diagnose a vitamin B12 deficiency?
A vitamin B12 deficiency can only be diagnosed by a doctor using a blood test. Here are some laboratory values that are important.
| Parameter | Normal value | Meaning |
| Vitamin B12 | > 300 pg/ml | Below 200 pg/mL Deficiency likely |
| Holotranscobalamin (Holo-TC) | > 35 pmol/l | Early marker for deficiency |
| Methylmalonic acid (MMA) | < 270 nmol/l | Increased in cases of functional deficiency |
| Homocysteine | < 10 µmol/l | Increased in B12 deficiency |
How important is vitamin B12 for longevity?
One of the most important functions of vitamin B12 is to support DNA synthesis and repair. It ensures that cells divide correctly and genetic information is passed on without errors. A lack of B12 leads to an accumulation of DNA damage, which accelerates cell aging and increases the long-term risk of age-related diseases. At the same time, B12 is involved in methylation processes that regulate genes and epigenetically influence how our body responds to environmental and lifestyle factors—a key aspect of healthy aging.
Vitamin B12 is also essential for the nervous system. It supports the formation of the myelin sheath, which protects nerve fibers and enables rapid signal transmission. A chronic deficiency can lead to nerve damage, memory problems, and an increased risk of neurodegenerative diseases such as Alzheimer’s. Studies show that people with low B12 levels are more likely to experience cognitive decline, especially when homocysteine levels are also elevated.
This connection is significant because vitamin B12, together with folic acid and vitamin B6, helps to lower homocysteine levels in the blood. Homocysteine is a substance that, when present in excess, promotes inflammation and vascular damage—a central mechanism in cardiovascular disease and age-related vascular deterioration. Well-regulated B12 levels can therefore indirectly have a positive effect on vascular health and thus on lifespan.
In addition, B12 supports energy production in the mitochondria, the “powerhouses” of the cells. It helps metabolic processes to run smoothly, reduces oxidative stress, and keeps cells functioning longer. The vitamin also has an effect on a psychological level: it plays a role in the formation of important neurotransmitters such as serotonin and dopamine, which influence our mood and stress resilience—two crucial factors for quality of life and healthy aging.
