Choline

The US Institute of Medicine officially recognized choline as an essential nutrient in 1998 [2]. It set an adequate intake of 425 mg a day for women, 450 mg for pregnant women, and 550 mg for men and for breastfeeding women [2]. People's choline needs vary, and common genetic variants explain part of that variation [2].

Choline is found in many foods. In the North American diet, eggs and meats are rich sources, with up to 430 milligrams per 100 grams [2]. A 2009 review of North American data reported that average intakes among older children, men, women and pregnant women were far below the adequate intake [2].

Inside the body, the main use of choline is making phosphatidylcholine, a membrane phospholipid [3]. Some is converted to betaine in the kidney and liver, and some becomes acetylcholine in the nervous system [3]. Cells take up choline through several transport systems [1]. The loop also runs the other way: when the enzyme acetylcholinesterase breaks down acetylcholine, one of the products is choline [4].

Several supplements are discussed as choline sources. Citicoline breaks down into cytidine and choline after it is swallowed [5]. Alpha-GPC is a natural breakdown product of phosphatidylcholine and serves as a source of choline, according to the European Food Safety Authority [6].

Being a choline source is chemistry, not a result. It does not by itself show that taking the supplement raises acetylcholine in the brain or changes memory or attention; each compound's monograph reports the human trials separately.

• Phosphatidylcholine: the main thing the body makes from choline.
• Phospholipid: the class of membrane fats choline helps build.
• Acetylcholinesterase: the enzyme that frees choline from acetylcholine.