Vitamins

Choline

By All The Nutrients Editorial Team Published: 8 min read

Choline is an essential nutrient classified with the B-vitamins but technically not a vitamin — the body can synthesise small amounts via the PEMT (phosphatidylethanolamine N-methyltransferase) enzyme pathway in the liver, but dietary intake is required to meet most needs. Choline serves three primary physiological roles: it is the structural backbone of phosphatidylcholine (the dominant phospholipid in cell membranes and lipoproteins), the precursor to the neurotransmitter acetylcholine (critical for neuromuscular junction function and memory), and a methyl donor (via its metabolite betaine) that participates in one-carbon metabolism alongside folate and B12. The richest dietary sources are eggs, beef liver, soybeans, beef, fish, and chicken.

Daily Value

550 mg

FDA 2020

Top Source

Egg, yolk, dried

2403 mg

What Does Choline Do?

  • Cell membrane integrity and structure: Phosphatidylcholine (PC) is the most abundant phospholipid in mammalian cell membranes (comprising ~50% of total membrane phospholipid in most cells) and is the dominant phospholipid in lipoproteins. PC maintains membrane fluidity, supports receptor function, and provides the platform for intracellular signalling cascades. Adequate choline intake is essential for membrane synthesis during rapid cell proliferation — making it particularly important during embryonic development, infancy, and pregnancy.
  • Neurotransmitter synthesis — acetylcholine: Choline is taken up by neurons (via choline transporters) and acetylated to acetylcholine — the primary neurotransmitter at neuromuscular junctions, in the autonomic nervous system (both sympathetic ganglia and parasympathetic), and in brain cholinergic circuits involved in memory, attention, and arousal. Cholinergic deficits are a hallmark of Alzheimer's disease. Adequate dietary choline is required to maintain acetylcholine synthesis, particularly in basal forebrain neurons.
  • Liver fat metabolism and VLDL secretion: Phosphatidylcholine is required for the assembly and secretion of VLDL (very-low-density lipoprotein) particles — the liver's mechanism for exporting newly synthesised triglycerides into the bloodstream. Without adequate choline, hepatic VLDL secretion fails, and triglycerides accumulate in liver cells, causing non-alcoholic fatty liver disease (NAFLD/MASLD). Choline deficiency is one of the most reproducible and well-characterised nutritional causes of fatty liver.
  • One-carbon metabolism and DNA methylation: Choline is converted in the liver to betaine, which donates a methyl group to homocysteine (converting it to methionine) — an alternative pathway to the folate/B12 methylation cycle. Methionine is then converted to SAM (S-adenosylmethionine), the universal methyl donor for DNA methylation, histone methylation, and dozens of other methyltransferase reactions. This interaction means choline adequacy affects epigenetic programming — particularly relevant in early embryonic development when genome-wide methylation patterns are being established.
  • Fetal brain development: Human observational studies show that choline intake during pregnancy — particularly in the second and third trimesters — correlates with improved cognitive outcomes in offspring. Animal studies demonstrate that choline supplementation during pregnancy produces permanent increases in brain hippocampal development and lifelong improvements in spatial memory and resistance to age-related cognitive decline. The mechanism involves choline's role in acetylcholine signalling during critical periods of fetal neuronal proliferation, migration, and synaptogenesis.
Horizontal bar chart of choline per 100g: beef liver 418mg, chicken liver 290mg, eggs 294mg, soybeans cooked 116mg, tofu firm 106mg, cod cooked 84mg, salmon cooked 79mg, beef cooked 78mg, broccoli 40mg. FDA DV reference line at 550mg.
Eggs and liver are the everyday champions. Plant eaters can close the gap with generous portions of soy-based foods, but reaching the AI requires deliberate planning.
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Signs of Choline Deficiency

Overt choline deficiency is relatively rare in free-living individuals eating varied diets, but is underdiagnosed because biochemical markers are not routinely measured. The most sensitive indicator is elevated plasma homocysteine or decreased plasma choline below 7 µmol/L. Clinical deficiency is most commonly encountered in:

  • Non-alcoholic fatty liver disease (NAFLD/MASLD) — the most reliable sign of choline deficiency; liver develops macrovesicular steatosis (fat droplets in hepatocytes) that reverses with choline repletion; seen in patients on total parenteral nutrition without choline, and in postmenopausal women (who lose oestrogen-dependent PEMT upregulation)
  • Muscle damage — plasma creatine kinase elevation from impaired cell membrane integrity in skeletal muscle; can cause myalgia and weakness
  • Neural tube defects — observational studies link low maternal choline intake to increased neural tube defect risk, independent of and additive to folate status
  • Impaired cognitive function — reduced acetylcholine synthesis affecting memory and attention; most pronounced in older adults with borderline intake
  • Elevated plasma homocysteine — from reduced betaine availability for homocysteine remethylation, increasing cardiovascular risk

How to Get the Most from Choline

Choline from food sources is generally well absorbed (about 50% of dietary choline reaches the systemic circulation), but form matters and gut microbiome interactions are important:

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Eggs are the most practical choline-rich food

Two large eggs provide approximately 294 mg of choline — 53% of the adequate intake for adult men and 69% for women. The choline is concentrated in the yolk as phosphatidylcholine and free choline. Egg yolk is also rich in lutein, zeaxanthin, and vitamin D — making eggs one of the most nutritionally dense everyday foods available.

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Gut microbiome converts choline to TMAO — context matters

Some gut bacteria (Clostridiales, Lachnospiraceae) convert choline to trimethylamine (TMA), which is absorbed and oxidised in the liver to trimethylamine N-oxide (TMAO). Elevated plasma TMAO is associated with increased cardiovascular risk in observational studies. However, the clinical significance of choline-derived TMAO is debated — fish is very high in TMAO itself yet associated with cardiovascular benefit. The microbiome composition determines how much choline is converted to TMAO vs. absorbed intact.

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Postmenopausal women need more choline from diet

Oestrogen upregulates the PEMT enzyme, which converts phosphatidylethanolamine to phosphatidylcholine (an endogenous choline synthesis pathway). Premenopausal women have higher PEMT activity and lower dietary choline requirements than men. After menopause, PEMT activity declines, and dietary choline requirements increase to levels equivalent to men (550 mg/day AI). This is why postmenopausal women on low-choline diets are particularly susceptible to choline deficiency-related fatty liver.

Common Choline Questions

How much choline do I need per day?

The FDA Daily Value for choline is 550 mg/day. The National Academies set an Adequate Intake (AI) — not an RDA, because data for establishing an EAR are insufficient — of 550 mg/day for adult men and 425 mg/day for adult women. The AI increases during pregnancy (450 mg/day) and breastfeeding (550 mg/day). The Tolerable Upper Intake Level (UL) is 3,500 mg/day for adults — the threshold above which body odour (fishy odour from excess TMAO), excessive sweating, nausea, vomiting, and low blood pressure have been reported. Most adults in the US consume less than the AI — median intake is around 300–350 mg/day for women and 400–500 mg/day for men — making choline one of the most widely underconsumed essential nutrients.

What foods are highest in choline?

Per 100 g: beef liver (418 mg), chicken liver (290 mg), eggs (294 mg per 100 g / 147 mg per large egg — concentrated in yolk at ~680 mg/100 g yolk), soybeans cooked (116 mg), beef cooked (78 mg), salmon cooked (79 mg), chicken breast cooked (66 mg), cod cooked (84 mg), shiitake mushrooms cooked (57 mg), milk (16 mg per 100 mL), broccoli cooked (40 mg). Eggs and liver are by far the richest everyday sources — two eggs provides more than half the AI for most adults.

Is choline important during pregnancy?

Very. Choline is essential for fetal brain development, neural tube closure, and placental function. The developing fetus concentrates choline — fetal plasma choline is 6–7 times higher than maternal plasma choline. The placenta actively transports choline against concentration gradients. Despite this, the average pregnant woman in the US consumes only about 320 mg/day — far below the 450 mg/day AI for pregnancy. Observational studies (Zeisel et al.) show that third-trimester choline intake positively predicts infant cognitive development and information-processing speed at 12 months. Many prenatal vitamins contain little or no choline — it is advisable to choose a prenatal supplement that explicitly includes 200–250 mg choline, or to ensure dietary sources cover the shortfall.

Can vegans get enough choline?

Choline adequacy on a vegan diet requires deliberate planning. The richest sources (eggs, liver, meat, fish) are excluded from vegan diets. Plant sources with meaningful choline content include: soybeans/edamame (116 mg/100 g cooked), tofu firm (106 mg/100 g), kidney beans (66 mg/100 g), quinoa (43 mg/100 g cooked), broccoli (40 mg/100 g), Brussels sprouts (41 mg/100 g), and shiitake mushrooms (57 mg/100 g). Achieving the 550 mg/day AI on a varied vegan diet including large portions of soy-based foods and multiple servings of choline-containing vegetables is feasible but challenging. A choline supplement (often sold as choline bitartrate or alpha-GPC) may be warranted, particularly during pregnancy and breastfeeding.

Does choline improve memory or cognitive function?

Adequate choline is required for acetylcholine synthesis in cholinergic neurons, and animal studies demonstrate dramatic cognitive benefits from perinatal choline supplementation. In adult humans, results are more nuanced. Studies in older adults show that higher dietary choline intake associates with better performance on tests of verbal memory and global cognition. A small number of RCTs using alpha-GPC (a highly bioavailable choline form) in mild cognitive impairment or early Alzheimer's disease show modest improvements in attention and memory. However, choline supplements do not reliably boost cognition in already-adequate healthy young adults. The clearest evidence for cognitive benefit is in the perinatal period (maternal choline during fetal brain development), not in normal adult supplementation.