Choline

Choline /ˈkoʊliːn/[1][2] is a water-soluble vitamin-like essential nutrient.[3][4][5] It is a constituent of lecithin, which is present in many plants and animal organs.[6] The term cholines refers to the class of quaternary ammonium salts containing the N,N,N-trimethylethanolammonium cation (X on the right denotes an undefined counteranion).[3]

The cation appears in the head groups of phosphatidylcholine and sphingomyelin, two classes of phospholipid that are abundant in cell membranes. Choline is the precursor for the neurotransmitter acetylcholine, which is involved in many functions including memory and muscle control.

Dietary sources of choline[edit]

Some animals cannot produce choline, but must consume it through their diet to remain healthy. Humans make a small amount of choline in the liver. In the United States, choline is recommended as an essential nutrient.[4][5] Possible benefits include reducing the risk of neural tube defects and fatty liver disease. It has also been found that intake of choline during pregnancy can have long-term beneficial effects on memory for the child.[5]

They have, however, published Adequate Intake (AI) values. The US Institute of Medicine (IOM) notes that these figures are based on just one study and that there was little data and the choline made by the body (assuming a dietary intake of zero) may be enough for some groups.[17] A

Neural tube closure[edit]

While folate is most well known for preventing neural tube nonclosure (the basis for its addition to prenatal vitamins), folate and choline metabolism are interrelated. Both choline and folate (with the help of vitamin B12) can act as methyl donors to homocysteine to form methionine, which can then go on to form SAM (S-Adenosyl methionine) and act as a methyl donor for methylation of DNA. Dietary choline deficiency alone without concurrent folate deficiency can decrease SAM concentration, suggesting that both folate and choline are important sources of methyl groups for SAM production.[25] Inhibition of choline absorption and

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Percentage of diet calculated using 2500 daily calories for an average adult male and 550mg for Adequate Intake (AI) using the figures from the table. As an example, even though peanuts contain some choline, they are a poor source given their 237% of diet to meet AI requirement, which means that a person who ate nothing but peanuts would have less than half of AI. Nearly identical figures are obtained for an average adult female when using 2000 calories and 425mg as assumptions; therefore, separate columns for male and female are not necessary.

References[edit]

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Oxford Dictionaries definition for Choline

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Merriam-Webster definition of Choline

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a b “Choline”. Human Metabolome Database. The Metabolomics Innovation Centre, University of Alberta, Edmonton, Canada. 17 August 2016. Retrieved 13 September 2016.

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a b c d e “Choline”. Micronutrient Information Center, Linus Pauling Institute, Oregon State University, Corvallis, Oregon. February 2015. Retrieved 10 January 2017.

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a b c d e f Zeisel SH; da Costa KA (November 2009). “Choline: an essential nutrient for public health”. Nutrition Reviews. 67 (11): 615–23. doi:10.1111/j.1753-4887.2009.00246.x. PMC 2782876pastedGraphic.png. PMID 19906248

Choline is a vitamin-like essential nutrient and a methyl donor involved in many physiological processes, including normal metabolism and transport of lipids, methylation reactions, and neurotransmitter synthesis. (More information)

•Choline deficiency causes muscle damage and abnormal deposition of fat in the liver, which results in a condition called nonalcoholic fatty liver disease. Genetic predispositions and gender can influence individual variation in choline requirements and thus the susceptibility to choline deficiency-induced fatty liver disease. (More information)

•The recommended adequate intake (AI) of choline is set at 425 milligrams (mg)/day for women and 550 mg/day for men. (More information)

•Choline is involved in the regulation of homocysteine concentration in the blood through its metabolite betaine. There is currently no convincing evidence that high choline intakes could benefit cardiovascular health through lowering blood homocysteine. Besides, elevated blood concentrations of trimethylamine N-oxide (TMAO), generated from choline, may increase the risk of cardiovascular events. (More information)

•The need for choline is probably increased during pregnancy. Case-control studies examining the relationship between maternal choline status and risk of neural tube defects (NTDs) have given inconsistent results. It is not yet known whether periconceptual choline supplementation could confer protection against NTDs. (More information)

•Animal studies have shown that choline is essential for optimal brain development and influences cognitive function in later life. However, in humans, there is not enough evidence to assert that choline supplementation during pregnancy improves offspring’s cognitive performance or that it helps prevent cognitive decline in older people. (More information)

•Recent intervention studies have found that supplementation with citicoline (a choline derivative) may be useful to limit neurologic damage in stroke patients and improve retinal function in some glaucoma patients. It remains unclear whether citicoline could be used in the treatment of dementias and in head trauma patients. (More information) 

De novo choline synthesis in humans is not sufficient to meet their metabolic needs. Good dietary sources of choline include eggs, meat, poultry, fish, cruciferous vegetables, peanuts, and dairy products. (More information)

•Excessive consumption of choline (≥7,500 mg) has been associated with blood pressure lowering, sweating, fishy body odor, and gastrointestinal side effects. The tolerable upper intake level (UL) for adults is 3,500 mg/day. (More information)

Although choline is not by strict definition a vitamin, it is an essential nutrient. Despite the fact that humans can synthesize it in small amounts, choline must be consumed in the diet to maintain health. The majority of the body’s choline is found in specialized fat molecules known as phospholipids, the most common of which is called phosphatidylcholine (1).

1.  Zeisel SH, Corbin KD. Choline. Present Knowledge in Nutrition. 10th ed: John Wiley & Sons, Inc.; 2012:405-418.

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