Choline, while closely related to the B complex family of vitamins, is not truely considered a vitamin since researchers cannot agree on any common definitions of deficiency symptoms. Choline is found in all living cells, and is known to play a vital role in maintaining the central nervous system and in numerous metabolic functions.
Choline is a component of lecithin and is used in the manufacture of cell membranes. It is also required for the production and metabolization of fats and cholesterol, and helps to protect the liver from the accumulation of excess fatty deposits. Choline’s most vital role may lie in its activity in the brain and central nervous system. Choline is a precursor of the important neurotransmitter acetylcholine, a chemical used in the transmission of brain impulses between nerves, muscles and organs. In this role it is involved directly with cognition, long and short term memory, stimulus response, and mental energy. Since acetylcholine levels increase rapidly after consuming choline, researchers have employed choline supplements in the treatment of various disorders marked by lowered levels of acetylcholine in the brain, including Huntington’s disease, Parkinson’s disease, Alzheimer’s disease, and tardive dyskinesia.
There is no recommended daily intake for choline. A deficiency of choline can result in increased fatty deposits in the liver, memory loss, and poor muscle coordination. While not toxic, excess consumption of choline can lead to over-stimulation of muscles, leading to tightening of the shoulders and neck, resulting in a tension headache.
Foods highest in choline include egg yolks, liver, meats, brewers yeast, milk, legumes and whole grain cereals. Choline can be manufactured in the human body with the help of vitamin Bl2, folic acid, and the amino acid called methionine, although not necessarily in optimal amounts. Choline is also available as a dietary supplement, in such forms as phosphatidylcholine, choline chloride, or choline bitartrate. Choline supplements should be avoided by persons who suffer from manic depression, as they may deepen the depressive phase of this disorder.