Quick Search
EC / List no.: 200-535-1
CAS no.: 62-49-7
Mol. formula: C5H14NO
Choline /ˈkoʊliːn/ is an essential nutrient for humans and many other animals.
Choline occurs as a cation that forms various salts (X− in the depicted formula is an undefined counteranion).
To maintain health, it must be obtained from the diet as choline or as choline phospholipids, like phosphatidylcholine.
Humans, as well as most other animal species, do make choline de novo, however production is generally insufficient. Choline is often not classified as a vitamin, but as a nutrient with an amino acid–like metabolism.
In most animals, choline phospholipids are necessary components in cell membranes, in the membranes of cell organelles, and in very low-density lipoproteins.
Choline is required to produce acetylcholine – a neurotransmitter – and S-adenosylmethionine, a universal methyl donor involved in the synthesis of homocysteine.
Symptomatic choline deficiency – rare in humans – causes nonalcoholic fatty liver disease and muscle damage.
Excessive consumption of choline (greater than 7.5 g/day) can cause low blood pressure, sweating, diarrhea and fish-like body odor due to trimethylamine, which forms in its metabolism.
Rich dietary sources of choline and choline phospholipids include organ meats and egg yolks, dairy products, peanuts, certain beans, nuts, seeds and vegetables with pasta and rice also contributing to choline intake in the American diet
Chemistry
The cholines are a family of water-soluble quaternary ammonium compounds.
Choline is the parent compound of the cholines class, consisting of ethanolamine having three methyl substituents attached to the amino function.
Choline hydroxide is known as choline base.
Choline is hygroscopic and thus often encountered as a colorless viscous hydrated syrup that smells of trimethylamine (TMA).
Aqueous solutions of choline are stable, but the compound slowly breaks down to ethylene glycol, polyethylene glycols, and TMA.
Choline chloride can be made by treating TMA with 2-chloroethanol:
(CH3)3N + ClCH2CH2OH → (CH3)3N+CH2CH2OH · Cl–
The 2-chloroethanol can be generated from ethylene oxide. Choline has historically been produced from natural sources, such as via hydrolysis of lecithin.
Metabolism
Biosynthesis
In plants, the first step in de novo biosynthesis of choline is the decarboxylation of serine into ethanolamine, which is catalyzed by a serine decarboxylase.
The synthesis of choline from ethanolamine may take place in three parallel pathways, where three consecutive N-methylation steps catalyzed by a methyl transferase are carried out on either the free-base, phospho-bases, or phosphatidyl-bases.
The source of the methyl group is S-adenosyl-l-methionine and S-adenosyl-l-homocysteine is generated as a side product.
Choline can also be released from more complex choline containing molecules.
For example, phosphatidylcholines (PC) can be hydrolyzed to choline (Chol) in most cell types.
Choline can also be produced by the CDP-choline route, cytosolic choline kinases (CK) phosphorylate choline with ATP to phosphocholine (PChol).
This happens in some cell types like liver and kidney.
Choline-phosphate cytidylyltransferases (CPCT) transform PChol to CDP-choline (CDP-Chol) with cytidine triphosphate (CTP).
CDP-choline and diglyceride are transformed to PC by diacylglycerol cholinephosphotransferase (CPT).
In humans, certain PEMT-enzyme mutations and estrogen deficiency (often due to menopause) increase the dietary need for choline.
In rodents, 70% of phosphatidylcholines are formed via the PEMT route and only 30% via the CDP-choline route.
In knockout mice, PEMT inactivation makes them completely dependent on dietary choline.
Absorption
In humans, choline is absorbed from the intestines via the SLC44A1 (CTL1) membrane protein via facilitated diffusion governed by the choline concentration gradient and the electrical potential across the enterocyte membranes.
SLC44A1 has limited ability to transport choline: at high concentrations part of it is left unabsorbed.
Absorbed choline leaves the enterocytes via the portal vein, passes the liver and enters systemic circulation.
Gut microbes degrade the unabsorbed choline to trimethylamine, which is oxidized in the liver to trimethylamine N-oxide.
Phosphocholine and glycerophosphocholines are hydrolyzed via phospholipases to choline, which enters the portal vein.
Due to their water solubility, some of them escape unchanged to the portal vein.
Fat-soluble choline-containing compounds (phosphatidylcholines and sphingomyelins) are either hydrolyzed by phospholipases or enter the lymph incorporated into chylomicrons.
Transport
In humans, choline is transported as a free molecule in blood.
Choline–containing phospholipids and other substances, like glycerophosphocholines, are transported in blood lipoproteins.
Blood plasma choline levels in healthy fasting adults is 7–20 micromoles per liter (μmol/l) and 10 μmol/l on average.
Levels are regulated, but choline intake and deficiency alters these levels.
Levels are elevated for about 3 hours after choline consumption.
Phosphatidylcholine levels in the plasma of fasting adults is 1.5–2.5 mmol/l.
Its consumption elevates the free choline levels for about 8–12 hours, but does not affect phosphatidylcholine levels significantly.
Choline is a water-soluble ion and thus requires transporters to pass through fat-soluble cell membranes.
Three types of choline transporters are known:
SLC5A7
CTLs: CTL1 (SLC44A1), CTL2 (SLC44A2) and CTL4 (SLC44A4)
OCTs: OCT1 (SLC22A1) and OCT2 (SLC22A2)
SLC5A7s are sodium- (Na+) and ATP-dependent transporters.
They have high binding affinity for choline, transport it primarily to neurons and are indirectly associated with the acetylcholine production.
CTL1s have moderate affinity for choline and transport it in almost all tissues, including the intestines, liver, kidneys, placenta and mitochondria.
CTL1s supply choline for phosphatidylcholine and trimethylglycine production.
CTL2s occur especially in the mitochondria in the tongue, kidneys, muscles and heart.
They are associated with the mitochondrial oxidation of choline to trimethylglycine.
CTL1s and CTL2s are not associated with the acetylcholine production, but transport choline together via the blood–brain barrier.
Only CTL2s occur on the brain side of the barrier.
They also remove excess choline from the neurons back to blood.
CTL1s occur only on the blood side of the barrier, but also on the membranes of astrocytes and neurons.
OCT1s and OCT2s are not associated with the acetylcholine production.
They transport choline with low affinity.
OCT1s transport choline primarily in the liver and kidneys; OCT2s in kidneys and the brain.
Storage
Choline is stored in the cell membranes and organelles as phospholipids, and inside cells as phosphatidylcholines and glycerophosphocholines.
Function
Choline and its derivatives have many functions in humans and in other organisms.
The most notable function is that choline serves as a synthetic precursor for other essential cell components and signalling molecules, such as phospholipids that form cell membranes, the neurotransmitter acetylcholine, and the osmoregulator trimethylglycine (betaine).
Trimethylglycine in turn serves as a source of methyl groups by participating in the biosynthesis of S-adenosylmethionine.
Phospholipid precursor
Choline is transformed to different phospholipids, like phosphatidylcholines and sphingomyelins.
These are found in all cell membranes and the membranes of most cell organelles.
Phosphatidylcholines are structurally important part of the cell membranes.
In humans 40–50% of their phospholipids are phosphatidylcholines.
Choline phospholipids also form lipid rafts in the cell membranes along with cholesterol.
The rafts are centers, for example for receptors and receptor signal transduction enzymes.
Phosphatidylcholines are needed for the synthesis of VLDLs: 70–95% of their phospholipids are phosphatidylcholines in humans.
Choline is also needed for the synthesis of pulmonary surfactant, which is a mixture consisting mostly of phosphatidylcholines.
The surfactant is responsible for lung elasticity, that is for lung tissue's ability to contract and expand.
For example, deficiency of phosphatidylcholines in the lung tissues has been linked to acute respiratory distress syndrome.
Phosphatidylcholines are excreted into bile and work together with bile acid salts as surfactants in it, thus helping with the intestinal absorption of lipids.
Acetylcholine synthesis
Choline is needed to produce acetylcholine.
This is a neurotransmitter which plays a necessary role in muscle contraction, memory and neural development, for example.
Nonetheless, there is little acetylcholine in the human body relative to other forms of choline.
Neurons also store choline in the form of phospholipids to their cell membranes for the production of acetylcholine.
Source of trimethylglycine
In humans, choline is oxidized irreversibly in liver mitochondria to glycine betaine aldehyde by choline oxidases.
This is oxidized by mitochondrial or cytosolic betaine-aldehyde dehydrogenases to trimethylglycine.
Trimethylglycine is a necessary osmoregulator.
Choline also works as a substrate for the BHMT-enzyme, which methylates homocysteine to methionine.
This is a S-adenosylmethionine (SAM) precursor.
SAM is a common reagent in biological methylation reactions.
For example, it methylates guanidines of DNA and certain lysines of histones.
Thus it is part of gene expression and epigenetic regulation.
Choline deficiency thus leads to elevated homocysteine levels and decreased SAM levels in blood.
Content in foods
Choline occurs in foods as a free molecule and in the form of phospholipids, especially as phosphatidylcholines.
Choline is highest in organ meats and egg yolks though it is found to a lesser degree in non-organ meats, grains, vegetables, fruit and dairy products.
Cooking oils and other food fats have about 5 mg/100 g of total choline.
In the United States, food labels express the amount of choline in a serving as a percentage of daily value (%DV) based on the adequate intake of 550 mg/day.
100% of the daily value means that a serving of food has 550 mg of choline.
Human breast milk is rich in choline. Exclusive breastfeeding corresponds to about 120 mg of choline per day for the baby.
Increase in a mother's choline intake raises the choline content of breast milk and low intake decreases it.
Infant formulas may or may not contain enough choline.
In the EU and the US, it is mandatory to add at least 7 mg of choline per 100 kilocalories (kcal) to every infant formula.
In the EU, levels above 50 mg/100 kcal are not allowed.
Trimethylglycine is a functional metabolite of choline.
Choline substitutes for choline nutritionally, but only partially.
High amounts of trimethylglycine occur in wheat bran (1,339 mg/100 g), toasted wheat germ (1,240 mg/100 g) and spinach (600–645 mg/100 g), for example.
Uses:
Choline chloride and choline bitartrate are used in dietary supplements.
Bitartrate is used more often due to its lower hygroscopicity.
Certain choline salts are used to supplement chicken, turkey and some other animal feeds.
Some salts are also used as industrial chemicals: for example, in photolithography to remove photoresist.
Choline theophyllinate and choline salicylate are used as medicines, as well as structural analogs, like methacholine and carbachol.
Radiolabeled cholines, like 11C-choline, are used in medical imaging.
Other commercially used salts include tricholine citrate and choline bicarbonate.
Antagonists and inhibitors
Hundreds of choline antagonists and enzyme inhibitors have been developed for research purposes.
Aminomethylpropanol is among the first ones used as a research tool.
Choline inhibits choline and trimethylglycine synthesis.
Choline is able to induce choline deficiency that in turn results in fatty liver in rodents.
Diethanolamine is another such compound, but also an environmental pollutant.
N-cyclohexylcholine inhibits choline uptake primarily in brains.
Hemicholinium-3 is a more general inhibitor, but also moderately inhibits choline kinases.
More specific choline kinase inhibitors have also been developed.
Trimethylglycine synthesis inhibitors also exist: carboxybutylhomocysteine is an example of a specific BHMT inhibitor.
The cholinergic hypothesis of dementia has not only lead to medicinal acetylcholinesterase inhibitors, but also to a variety of acetylcholine inhibitors.
Examples of such inhibiting research chemicals include triethylcholine, homocholine and many other N-ethyl derivates of choline, which are false neurotransmitter analogs of acetylcholine.
Choline acetyltransferase inhibitors have also been developed.
Choline is a nutrient similar to B vitamins.
Choline can be made in the liver.
Choline is also found in foods such as meats, fish, nuts, beans, vegetables, and eggs.
Choline is used in many chemical reactions in the body.
It's important in the nervous system and for the development of normal brain functioning.
Choline might also help decrease swelling and inflammation related to asthma.
Chemical Properties
Viscous, alkaline liquid. Soluble in water and alcohol.
Amounts are expressed in milligrams of choline.
Uses:
Choline is a substance grouped as a member of the vitamin b complex, although not a vitamin by definition.
Choline is water soluble and is important in nerve function and fat metabolism.
Choline occurs in egg yolk, beef liver, and grains.
Choline is a choline that is the parent compound of the cholines class, consisting of ethanolamine having three methyl substituents attached to the amino function.
Choline has a role as a neurotransmitter, a nutrient, a human metabolite, a plant metabolite, a Daphnia magna metabolite, a Saccharomyces cerevisiae metabolite, an Escherichia coli metabolite, a mouse metabolite and an allergen.
Choline is a natural product found in Capsella bursa-pastoris, Caulerpa racemosa, and other organisms with data available.
A basic constituent of lecithin that is found in many plants and animal organs.
Choline is important as a precursor of acetylcholine, as a methyl donor in various metabolic processes, and in lipid metabolism.
Choline is an essential nutrient.
This means it’s required for normal bodily function and human health.
Though your liver can make small amounts, you must obtain the majority through your diet.
Choline is an organic, water-soluble compound.
Choline is neither a vitamin nor a mineral.
However, it is often grouped with the vitamin B complex due to its similarities.
In fact, this nutrient affects a number of vital bodily functions.
Choline impacts liver function, healthy brain development, muscle movement, your nervous system and metabolism.
Therefore, adequate amounts are needed for optimal health (1).
Choline is an essential nutrient that must be included in your diet to maintain optimal health.
Choline plays an important part in many processes in your body, including:
Cell structure: Choline is needed to make fats that support the structural integrity of cell membranes.
Cell messaging: Choline is involved in the production of compounds that act as cell messengers.
Fat transport and metabolism: Choline is essential for making a substance required for removing cholesterol from your liver. Inadequate choline may result in fat and cholesterol buildup in your liver.
DNA synthesis: Choline and other vitamins, such as B12 and folate, help with a process that’s important for DNA synthesis.
A healthy nervous system: This nutrient is required to make acetylcholine, an important neurotransmitter. It’s involved in memory, muscle movement, regulating heartbeat and other basic functions.
Choline is involved in many different processes, such as cell structure and messaging, fat transport and metabolism, DNA synthesis and nervous system maintenance.
Choline is an essential nutrient that is naturally present in certain foods and available as a supplement.
The body can also produce small amounts on its own in the liver, but not enough to meet daily needs.
Choline is converted into a neurotransmitter called acetylcholine, which helps muscles to contract, activates pain responses, and plays a role in brain functions of memory and thinking.
Most choline is metabolized in the liver where it is converted into phosphatidylcholine, which assists in building fat-carrying proteins and breaking down cholesterol.
Choline is an essential nutrient that supports vital bodily functions and people’s overall health. Although the body makes some choline, people need to incorporate choline-rich foods into their diet to get enough of it.
Choline supports numerous vital bodily functions, including:
Cell maintenance: The body uses choline to produce fats that make up cellular membranes.
DNA synthesis: Choline, along with other nutrients such as folate and vitamin B-12, can affect gene expression.
Metabolism: Choline helps metabolize fats.
Nervous system functioning: The body converts choline into a neurotransmitter that affects the nerves and plays a role in regulating automatic bodily functions, such as breathing and heart rate.
Choline exists as both water-soluble and fat-soluble molecules. The body transports and absorbs choline differently depending on its form.
Water-soluble choline molecules go to the liver, where the body converts them into a type of fat called lecithin.
Fat-soluble choline usually comes from dietary sources, so the body absorbs it in the gastrointestinal tract.
Benefits
Choline supports several vital bodily functions and may offer a wide range of other health benefits, such as:
Improving memory and cognition
Choline is an essential nutrient for brain development.
In one observational study of 2,195 participants aged 70–74 years, those with higher choline levels had better cognitive functioning than participants with low choline levels.
Another observational study from 2019 found that inadequate levels of choline, vitamin C, and zinc were associated with poorer working memory in older men.
Protecting heart health
The authors of a 2018 study found an association between higher dietary intakes of choline and a lower risk of ischemic stroke.
The study looked at nearly 4,000 African American participants, with an average 9 year follow-up period.
Boosting metabolism
Some research has shown that choline plays a role in metabolizing fats.
The authors of a small 2014 study found that female athletes who took choline supplements had lower body mass indexes (BMIs) and leptin levels than the control group.
Leptin is a hormone that controls body fat.
Choline is an essential nutrient that supports your lipid metabolism and liver health.
Your liver produces some choline, but most of the choline your body needs comes from the food you eat.
Your body needs choline to function properly.
Choline helps:
Your brain and central nervous system control your memory and mood.
Your liver and muscles work correctly.
Your cells form and repair their membranes.
Your lipids break down and convert into energy.
Choline is a part of many chemicals within the body.
It’s water-soluble. All of the jobs of choline are not yet known.
Choline may be needed for your liver and kidneys to work well.
Choline is also a part of the neurotransmitter acetylcholine.
This is a chemical that passes messages between nerves.
Choline also passes messages between nerves and muscles.
Choline is also the building block of lecithin and sphingomyelins.
Lecithin is a part of cell walls, plasma, and lipoproteins.
Sphingomyelin is the insulating material of brain and nerve tissue.
Mechanism of action
Choline is a major part of the polar head group of phosphatidylcholine.
Phosphatidylcholine's role in the maintenance of cell membrane integrity is vital to all of the basic biological processes, information flow, intracellular communication and bioenergetics.
Inadequate choline intake would negatively affect all these processes.
Choline is also a major part of another membrane phospholipid, sphingomyelin, also important for the maintenance of cell structure and function.
Choline is noteworthy and not surprising that choline deficiency in cell culture causes apoptosis or programmed cell death.
This appears to be due to abnormalities in cell membrane phosphatidylcholine content and an increase in ceramide, a precursor, as well as a metabolite, of sphingomyelin.
Ceramide accumulation, which is caused by choline deficiency, appears to activate Caspase, a type of enzyme that mediates apoptosis.
Betaine or trimethylglycine is derived from choline via an oxidation reaction.
Betaine is one of the factors that maintains low levels of homocysteine by resynthesizing L-methionine from homocysteine.
Elevated homocysteine levels are a significant risk factor for atherosclerosis, as well as other cardiovascular and neurological disorders.
Acetylcholine is one of the major neurotransmitters and requires choline for its synthesis.
Adequate acetylcholine levels in the brain are believed to be protective against certain types of dementia, including Alzheimer's disease.
About Choline
Helpful information
Choline is registered under the REACH Regulation and is manufactured in and / or imported to the European Economic Area, for intermediate use only.
Choline is used at industrial sites and in manufacturing.
Consumer Uses
ECHA has no public registered data indicating whether or in which chemical products the substance might be used.
ECHA has no public registered data on the routes by which Choline is most likely to be released to the environment.
Article service life
ECHA has no public registered data on the routes by which Choline is most likely to be released to the environment.
ECHA has no public registered data indicating whether or into which articles the substance might have been processed.
Widespread uses by professional workers
ECHA has no public registered data indicating whether or in which chemical products the substance might be used. ECHA has no public registered data on the types of manufacture using Choline. ECHA has no public registered data on the routes by which Choline is most likely to be released to the environment.
Formulation or re-packing
ECHA has no public registered data indicating whether or in which chemical products the substance might be used. ECHA has no public registered data on the routes by which Choline is most likely to be released to the environment.
Uses at industrial sites
ECHA has no public registered data indicating whether or in which chemical products the substance might be used.
ECHA has no public registered data on the types of manufacture using Choline.
ECHA has no public registered data on the routes by which Choline is most likely to be released to the environment.
Manufacture
ECHA has no public registered data on the routes by which Choline is most likely to be released to the environment.
IUPAC NAMES:
2-(trimethylamino)ethan-1-ol
2-hydroxy-N,N,N-trimethylethanaminium
2-hydroxyethyl(trimethyl)azanium
2-hydroxyethyl-trimethyl-ammonium
Choline
choline
SYNONYMS:
2,4,6-TRIS(4-FLUOROPHENYL)PYRYLIUM TETRAFLUOROBORATE
Choline Base Aqueous
Choline Base Aqueous 45%
Choline Base In Methanol
CHOLINE
CHOLINE, BASE
cholineion
beta-Hydroxyethyltrimethylammonium hydroxide
Choline solution 50 % in water
CHOLINE BASE APPROX. 50% (W/W) AQUEOUSSO LUTION
CholineBitartrateFcc
CholineBitartrateCoated98%
ChlolineBitartarate
Choline Bitartrate Coated 98%
stabilized45wt%solutioninmethanol
CHOLINE (48-50% IN WATER)
Ethanaminium, 2-hydroxy-N,N,N-trimethyl-
CHOLINEBASE,45%(W/W)SOLUTIONINMETHANOL
LOW-CHOLINEDIET
Sincalin
Trimethyl-2-hydroxyethylammonium salt
2,6-DI-TERT-BUTYL-4-(4-METHOXY-PHENYL)-PYRANYLIUM, TETRAFLUORO BORATE
HYDROXYETHYLTRIMETHYLAMMONIUM HYDROXIDE
(2-hydroxyethyl)trimethylammonium
2-hydroxy-n,n,n-trimethyl-ethanaminiu
2-hydroxy-n,n,n-trimethylethanaminium
2-hydroxy-N,N,N-trimethyl-Ethanaminium
bilineurine
cholinecation
CHOLINE Base (Hydroxide)
CHOLINE USP/EP/BP
L-Choline
choline
Choline ion
Bilineurine
62-49-7
Choline cation
Cholinum
2-Hydroxy-N,N,N-trimethylethanaminium
Ethanaminium, 2-hydroxy-N,N,N-trimethyl-
(2-Hydroxyethyl)trimethylammonium
trimethylethanolamine
N-trimethylethanolamine
2-hydroxyethyl(trimethyl)azanium
CCRIS 5847
AI3-24208
UNII-N91BDP6H0X
BRN 1736748
N,N,N-trimethylethanol-ammonium
CHEBI:15354
(beta-hydroxyethyl)trimethylammonium
CHEMBL920
N91BDP6H0X
(2-hydroxyethyl)trimethylazanium
2-hydroxy-N,N,N-trimethyl-ethanaminium
Bilineurine; Choline cation; Choline ion; Nanoveson C; Vitamin J
vitamin J
CHT
NSC402838
NCGC00015219-03
EINECS 200-535-1
2-hydroxyethyl(trimethyl)ammonium
Choline (DCF)
Choline (8CI)
3-04-00-00651 (Beilstein Handbook Reference)
N,N,N-trimethylethanolammonium
(2-Hydroxyethyl)trimethyl ammonium
mono-2-hydroxyethyltrimethylammonium
2-Hydroxy-N,N,N-trimethylammonium chloride
Ethanaminium, 2-hydroxy-N,N,N-trimethyl- (9CI)
