Most commonly found in eggs, choline is often classified with the B vitamin complex as it has some similar functions.
It was officially recognised as an essential nutrient by the US Institute of Medicine in 1998, with a recommended intake of 425mg. The new European Adequate Intake (AI) level is for 400mg daily.
Recent research has shown that the central nervous system is particularly sensitive to a lack of choline, with effects on the structure of the brain and spinal cord, as well as cognition.
An average medium size egg provides 144mg of choline.