Choline is an essential, vitamin-like nutrient that helps keep your brain and nervous system working smoothly. It is a key building block for acetylcholine - one of the main neurotransmitters involved in memory, focus and muscle control - and it also helps maintain healthy cell membranes and normal liver function. Because your body can only make a small amount of choline on its own, regularly including choline-rich foods like eggs, meat, fish, and some beans and nuts is an important way to support long-term brain and metabolic health.