Methylcobalamin B12 is involved in the production of acetylcholine, a neurotransmitter essential for memory, learning

https://zenwriting.net/morianzegg/what-you-need-to-know-about-high-levels-of-vitamin-b12-in-the-blood

Methylcobalamin B12 is involved in the production of acetylcholine, a neurotransmitter essential for memory, learning, and muscle function