The B vitamins are not called “nerve vitamins” for nothing. They not only have an effect on the nerves themselves, but also on the psyche. The vitamin with the number 12 is the most important B vitamin.

“Vitamin B12 is one of the most important vitamins for our cells – without vitamin B12 there is no cell division, so no growth, no new red blood cells and no functioning nervous system. Healing is only possible with B12.

Where B12 comes from: Vitamin B12 is formed by the bacterial flora in the digestive tract and is therefore only found in animal products: mainly in offal, meat, fish and dairy products. Algae-based alternatives also contain B12, but only as analogs with no vitamin effect. Although our intestinal flora can actually produce some of the vitamin B12 we need, this is not enough to ensure a complete supply.

What B12 can do: Vitamin B12 converts the important cell vitamin folic acid into its active form. It plays a key role in the construction of red blood cells and ensures the incorporation of iron. Vitamin B12 deficiency leads to anaemia: the blood cells change their shape, those affected look pale and are tired. Neurological disorders such as tingling and numbness can also occur; even mental disorders and even depression. Methylation processes do not work with vitamin B12 deficiency. As a result, homocysteine cannot be recycled and rises dangerously, and the production of neurotransmitters also suffers. Because vitamin B12 is stored in the liver over the long term, deficiencies, for example in strict vegans, sometimes only become apparent after months or years – but can then have serious consequences.” Source: Dr. Ulrich Strunz: New miracle of healing and

Have your levels measured: You can have your vitamin B12 level measured. The reference range is very broad, between 197 – 771 pg/ml. Values below 200 pg/ml are considered a deficiency. There are also doctors who consider values of over 1,000 pg/ml to be desirable. Since the reference range is very broad, I personally consider values in the upper range to be more useful than in the lower reference range.

It is best to take a vitamin B complex: The B vitamins form a whole family and consist of eight different B vitamins. As they all interact with each other, people with mental health problems benefit from all of them together. Such products are marketed as “vitamin B complex”.

Here I present two studies that were published in 2020 and 2021. In a

Overview of the influence of supplementation and nutritional interventions on the pathogenic processes of mood disorders” (the original study can be found here: and my translation of the text into German can be found in the blog under “scientific studies”) states that

  • Altered B12 levels are associated with inflammatory conditions that lead to psychiatric disorders, including depression
  • Inflammation and depressive symptoms have a bidirectional relationship that favors and promotes each other
  • Vitamins B9 (folate) and B12 reduce homocysteine levels
  • High homocysteine levels of over 10 µmol/l are an indicator of a B9 and B12 deficiency, as folate and vitamin B12 are involved in the conversion of homocysteine into methionine
  • Homocysteine is crucial for the formation of neurotransmitters, so altered homocysteine levels can affect mood
  • Folate and/or vitamin B12 supplementation lowers homocysteine, which can contribute to improved methylation and neurotransmitter metabolism and release
  • Hyperhomocysteinemia (i.e., an increase in serum homocysteine concentration above normal plasma or serum homocysteine levels) is associated with a risk of vascular disease, impaired bone remodeling, cancer, Parkinson’s disease, Alzheimer’s dementia, mental retardation, and signs and symptoms of neurological dysfunction, including major depression and schizophrenia

A study from Jena was published in July 2020,

Acute vitamin B12 supplementation triggers an antidepressant response and alters the gene Ntrk-2” (the original study can be found here and my translation of the text into German can be found in the blog under “scientific studies”)

which, although only on mice, proved that a single dose of vitamin B12 24 hours later improved depression-like behavior in mice. The reason given for this is that acute supplementation with vitamin B12, but not with folic acid, selectively altered DNA methylation and Ntrk-2 gene expression in vitro, although DNA methylation and Ntrk-2 gene expression do not correlate in vivo. This Ntrk-2 gene encodes the BDNF receptor.

What is BDNF?

“The growth factor BDNF (brain-derived neurotrophic factor) is produced in the mature brain, primarily in the hippocampus. Here it plays an important role in long-term memory and abstract thinking. Patients with depression show reduced BDNF blood levels. Psychosocial stress is also associated with lower serum BDNF. One reason for this is that stress inhibits the expression of BDNF, probably via the secretion of the stress hormone cortisol. Chronic stress can therefore reduce BDNF levels even before neuroanatomical changes manifest themselves. … In addition to the classic antidepressants, other preparations can also cause an increase in BDNF serum levels. The administration of omega-3 fatty acids, zinc and vitamin E is associated with an increase in the BDNF serum level, whereas polyunsaturated fats and sugar reduce the blood level. Sleep regulation and stress reduction can

also be associated with an increase in BDNF.”

Source: “BDNF – a serum marker for depression and burnout” Diagnostic information no. 302 of the Institute for Medical Diagnostics Berlin IMD.

You can watch a presentation on this free of charge and without registration in the video archive at

The BDNF receptor is influenced by vitamin B12 and thus has an antidepressant effect.

That’s exciting – isn’t it?