Actually the brain needs to metabolize neurotransmitters, and to do this it produces ‘S adenosylmethionine’, for which B12 is a very important part of production.
Norepinephrine is an essential neurotransmitter for maintaining a positive mood, and those who are deficient in B12 have shown to be more prone to depression and similar neuropsychiatric symptoms.
Diseases similar to pernicious anemia and dementia, that are most common in the elderly, have also been linked to B12 deficiencies. Sadenosylmethionine is what most people know to be called Serotonin, and is an important neurotransmitter in the brain. Moodiness, sexual arousal, body temperature, skin problems, insomnia and headaches, without adequate serotonin levels a person will have trouble with controlling their emotions. I know it’s a fairly common fact that those who suffer from depression struggle with serotonin. a lot of studies are conducted that have proven supplementing B12 and folic acid simultaneously in depression patients together with an ideal dietary intake will elevate moods dramatically.