Did you know…

Choline is a nutrient that the body cannot manufacture in adequate amounts, that must be obtained from food, and that most people do not consume enough of. It is required for the structure of every cell membrane, for the transmission of signals in the parasympathetic nervous system, and for the osmotic defence of the cells that manage the water balance of the entire body. It is not measured in ordinary primary care.

The claim, in the words of the researcher who established essentiality

Steven Zeisel of the University of North Carolina at Chapel Hill did the laboratory work that led the Institute of Medicine to classify choline as an essential nutrient in 1998. In the Annual Review of Nutrition in 2006, he wrote what has become the standard reference on the state of population intake:

“Choline is a required nutrient for humans; it must be consumed in the diet to maintain health. Yet current dietary intakes for most people are well below the levels considered adequate.”

— Steven Zeisel, Annual Review of Nutrition, 2006

Why the intake gap matters, in three roles

Choline serves at least three roles the body cannot substitute for at scale. First, as phosphatidylcholine, it is a structural component of every cell membrane, and hepatic phosphatidylcholine synthesis via the PEMT pathway is one of the two largest consumers of the methyl-transfer economy. Second, as acetylcholine, it is the neurotransmitter of the parasympathetic nervous system: without adequate acetylcholine, the body cannot fully descend from sympathetic tone into rest, repair, and digestion. Third, as betaine, it is the compatible osmolyte that allows the kidney medulla to survive the extreme osmotic gradient it lives in, and the alternative remethylation route (BHMT) that reduces homocysteine.

What routine care measures

Nothing. Ordinary blood panels do not include choline, betaine, or phosphatidylcholine. The intake deficit documented by Zeisel two decades ago has not entered the dietary assessment step of a primary care visit. Physicians who ask about protein and carbohydrate do not, in the same appointment, ask about eggs, liver, or the specific plant sources that carry enough choline to matter.

This entry is a companion to Right to Optimal Choline Status.