Choline - definition from Biology-Online.org
[(Science: biochemistry) Esterified in the head group of phospholipids (phosphatidylcholine and sphingomyelin) and in the neurotransmitter acetylcholine. Otherwise a biological source of methyl groups.
MediLexicon choline - Medical Dictionary Definition for Term 'choline'
[1. agent found in most animal tissues either free or in combination as lecithin (phosphatidylcholine), acetate (acetylcholine), or cytidine diphosphate (cytidine diphosphocholine). It is included in the vitamin B complex. Several salts of choline are used in medicine.