What role does B12 play in Schlaf?

Vitamin B12 plays a role in the synthesis of neurotransmitters such as serotonin and melatonin, which help regulate the sleep-wake cycle. It also supports myelination of nerve fibers, facilitating efficient neural signaling. Some observational studies have linked low B12 levels with sleep disturbances like insomnia or poor sleep quality, but the evidence is largely mechanistic and insufficient for clinical recommendations. B12 deficiency can cause fatigue and lethargy, which may indirectly affect sleep, but direct causal effects on sleep architecture in humans are not well established. Most data come from animal models or small human studies. Routine B12 testing for sleep complaints is not advised unless deficiency risk factors (e.g., vegan diet, malabsorption) are present. Overall, B12's role in sleep is supportive rather than primary, and the evidence base remains weak.