Choline: Benefits, Best Forms, Dosing, and Side Effects

Table of Contents

• Overview
• Forms and Bioavailability
• Evidence for Benefits
• Recommended Dosing
• Safety and Side Effects
• Drug Interactions
• Dietary Sources
• References

Overview

Choline is an essential nutrient required for cell membrane structure, neurotransmitter synthesis, lipid transport, and methyl group metabolism. It is a precursor to phosphatidylcholine and sphingomyelin — two major phospholipids vital for the structural integrity of all plant and animal cell membranes [1][2]. Choline is also required for the synthesis of acetylcholine, a neurotransmitter critical for memory, mood, muscle control, and other brain and nervous system functions [1][2][3]. Beyond these roles, choline participates in modulating gene expression through epigenetic mechanisms (DNA and histone methylation), lipid transport from the liver, and early brain development [1][2].

Humans can produce choline endogenously in the liver, primarily through the phosphatidylethanolamine N-methyltransferase (PEMT) pathway, but the amount synthesized is insufficient to meet total needs [4]. This de novo synthesis accounts for approximately 30% of the phosphatidylcholine formed in the liver [5]. As a result, choline has been recognized as an essential nutrient since 1998, when the Institute of Medicine established dietary recommendations for intake [2].

Choline deficiency is widespread. Most people in the United States consume less than the Adequate Intake (AI) for choline. An analysis of 2013–2014 NHANES data found that average daily choline intake from foods and beverages is 402 mg in men and 278 mg in women — both below the AI of 550 mg and 425 mg respectively [6]. A 2005 US government survey indicated that only 2% of postmenopausal women consumed the recommended intake of choline [7][8]. Choline intake also tends to decrease with age: adults aged 71 and older consumed an average of about 264 mg per day — roughly half the AI [9].

Several groups are at elevated risk of choline inadequacy:

• Postmenopausal women: Estrogen plays a role in choline production via the PEMT pathway. After menopause, reduced estrogen levels decrease endogenous choline synthesis, increasing dietary requirements [4][7].
• Pregnant and lactating women: Approximately 90–95% of pregnant women consume less choline than the AI. Large amounts of choline are transferred from the mother to the fetus during pregnancy and to the infant during lactation, which can deplete maternal choline levels [6][9][10].
• People with certain genetic polymorphisms: Common SNPs in genes involved in choline metabolism (PEMT, CHDH, MTHFD1) can substantially increase dietary choline requirements. One common SNP in the PEMT gene reduces estrogen-induced endogenous choline synthesis. The prevalence of these SNPs varies by race; individuals of European ancestry had a higher prevalence of four SNPs that increased the risk of organ dysfunction on a low-choline diet [11][12].
• Patients receiving total parenteral nutrition (TPN): Choline is not routinely added to commercial parenteral solutions, and adults and infants on long-term TPN develop low plasma choline concentrations and hepatic abnormalities [13][14].
• People with low folate intake: When dietary folate is deficient, choline becomes the primary methyl donor, increasing the need for dietary choline [1].

Choline deficiency can cause muscle damage, liver damage, and nonalcoholic fatty liver disease (NAFLD) [1][2][4][15]. Inadequate intake may also contribute to atherosclerosis and neurological disorders [9]. Although frank choline deficiency in healthy men and nonpregnant women is rare — possibly due to endogenous synthesis — subclinical inadequacy is a significant public health concern given how few people meet the AI [1][15].

Choline status is not routinely measured in healthy people. In healthy adults, plasma choline concentrations range from 7 to 20 micromol/L, with fasting adults typically at 7–9.3 micromol/L [2][16]. Plasma choline levels do not decline below 50% of normal even in individuals who have not eaten for more than a week, likely due to hydrolysis of membrane phospholipids to maintain a minimum concentration [2].

Forms and Bioavailability

Not all choline supplements are equivalent. The form determines how much actual choline is delivered per gram of compound, how well it is absorbed, and what downstream metabolic effects it produces — particularly regarding TMAO production (discussed in Safety).

Comparison of Choline-Containing Ingredients

Form	Chemical Name	% Choline	Key Notes
Lecithin	Lecithin	2–3%	Mixture of phospholipids; 14–21% phosphatidylcholine, of which 13.7% is choline. 2 teaspoons (4 g) provides ~134 mg choline [17].
Phosphatidylcholine	Phosphatidylcholine	13.7%*	Major dietary form. Better absorbed than choline bitartrate; does NOT raise TMAO levels [18][19].
CDP-choline (Citicoline)	Cytidine diphosphate-choline	21.4%	Breaks down to release choline and uridine. Uridine aids phospholipid synthesis for neuronal membrane maintenance. Less likely to raise TMAO than choline bitartrate [20][21].
Alpha-GPC	L-alpha glycerylphosphorylcholine	40.3%	High bioavailability, ~90% absorption in animal studies. Effective blood-brain barrier penetration. Linked to increased stroke risk with long-term use [22][23].
Choline Bitartrate	Choline bitartrate	41.1%	High choline per gram but poorly absorbed in the gut. Unabsorbed choline converted to TMAO by gut bacteria. Associated with kidney stones at high doses [18][19][24].
Choline Citrate	Choline dihydrogen citrate	37.4%	Used in clinical asthma trials. Intermediate between bitartrate and phosphatidylcholine forms [17].
Choline Chloride	Choline chloride	74.6%	Highest choline concentration. GRAS status since 1975 but not currently available as a dietary supplement in the US [17].

*For phosphatidylcholine, % choline may vary by approximately 0.5% depending on specific fatty acid composition.

Absorption and TMAO Considerations

A study comparing choline absorption showed that 3 grams of choline from an egg yolk phospholipid drink was absorbed four times better than 3 grams of choline from choline bitartrate [25]. This difference matters not only for efficacy but for safety: choline that is not absorbed can be converted by gut bacteria into trimethylamine (TMA), which the liver then converts to TMAO — a compound associated with increased cardiovascular risk [18][19].

Phosphatidylcholine and lecithin are preferentially absorbed intact in the small intestine, incorporated into chylomicrons, and secreted into lymphatic circulation, where they are distributed to tissues including the brain and placenta [1][2]. This pathway largely bypasses gut bacterial metabolism, which is why these forms do not raise TMAO.

CDP-choline (citicoline) is theorized to be less prone to TMAO conversion based on animal studies showing citicoline is less toxic than choline chloride when given orally, which may be due to absorption of intact citicoline from the GI tract [20]. However, at least one rat study identified TMA in the urine of citicoline-treated rats, indicating some conversion does occur [26].

Choline bitartrate is poorly absorbed in the gut, leaving more available for microbial conversion to TMA and then TMAO. A Cleveland Clinic study in healthy adults showed that choline bitartrate supplementation (411 mg/day total choline) increased fasting TMAO levels by about 71% over one month and also increased platelet aggregation — a risk factor for atherosclerosis [18]. Another study found that 450 mg of choline from choline bitartrate twice daily increased plasma TMAO levels more than 10-fold in vegans/vegetarians and 14-fold in omnivores [19]. By contrast, phosphatidylcholine supplements providing a similar amount of total choline did not increase fasting TMAO levels [18][27].

Alpha-GPC has limited and mixed evidence regarding TMAO [28][29], but a large observational study linked long-term alpha-GPC use with increased stroke risk (discussed in Safety).

Key Principles for Form Selection

For general supplementation to meet AI: Phosphatidylcholine or lecithin are safe, well-absorbed forms that do not raise TMAO. Choline bitartrate provides high choline per gram but carries TMAO concerns.

For cognitive support: CDP-choline (citicoline) has the most clinical trial evidence for memory and attention. Alpha-GPC has evidence for Alzheimer's disease but carries stroke risk with long-term use.

For pregnancy: Choline chloride was used in the key maternal supplementation trials, but phosphatidylcholine from dietary sources (especially eggs) or supplements is a practical alternative.

For minimizing TMAO risk: Phosphatidylcholine, lecithin, and possibly citicoline are preferred. Avoid high-dose choline bitartrate, particularly in individuals at cardiovascular risk.

Dr Brad Stanfield's MicroVitamin includes 181.5 mg of choline as choline bitartrate, providing a moderate dose intended to help close the widespread dietary gap in choline intake. At this level — well below the doses shown to significantly elevate TMAO in clinical studies — the form offers a practical way to contribute toward the Adequate Intake when combined with dietary choline from foods like eggs.

Evidence for Benefits

Fatty Liver Disease (NAFLD)

Choline is essential for transporting lipids from the liver via phosphatidylcholine-dependent VLDL assembly. When choline is deficient, fat accumulates in the liver, resulting in nonalcoholic fatty liver disease [1][15][30].

Choline deficiency causes NAFLD directly. In a study of 57 adults fed a diet containing less than 50 mg choline per 70 kg body weight per day (less than 10% of the AI) for up to 42 days, 37 participants developed liver dysfunction. Liver function returned to normal after refeeding with a diet containing 25–75% of the choline AI [31].

Observational evidence in Chinese adults. A cross-sectional study of 56,195 Chinese adults aged 40–75 found an inverse relationship between dietary choline intake and risk of NAFLD. The risk was 32% lower in women in the highest quintile of choline intake (412 mg/day) compared to the lowest (179 mg/day), and 25% lower in men in the highest quintile (452 mg/day) versus the lowest (199 mg/day). In women, this association was present only in those of normal weight [32].

Postmenopausal women with NASH. In a cross-sectional study of 664 adults and children, postmenopausal women with nonalcoholic steatohepatitis who had choline intake less than 50% of the AI had more severe fibrosis [33].

Total parenteral nutrition. Choline given intravenously has been shown to be effective for treating TPN-associated hepatic steatosis. A pilot study in 15 adults on TPN found that NAFLD resolved completely in all patients who received an additional 2 g choline with their usual regimen and in none who received the usual regimen alone [14][34].

Genetic susceptibility. The risk of choline-deficiency-related NAFLD may be increased in people with certain genetic types affecting enzymes in choline metabolism (CHDH, MTHFD1, PEMT). At least 40% of women of childbearing age have a polymorphism (PEMT) that makes them insensitive to estrogen-mediated activation of the gene, making adequate dietary choline particularly important for this population [8][35].

Limitation. Despite the strong evidence that choline deficiency causes NAFLD, there do not appear to be clinical trials on the effects of oral choline supplementation for the prevention or treatment of established NAFLD in the general population [17].

Stroke

Treatment with CDP-choline (citicoline) within the first 24 hours after onset in patients with moderate to severe ischemic stroke increases the probability of complete recovery at 3 months by approximately 30%, according to an analysis of several clinical trials. The most effective dose was 2,000 mg daily of CDP-choline (providing 428 mg of choline) [36].

Memory and Cognition

Several studies have evaluated the impact of choline on memory and cognition. Results have been generally mixed, with the most promising evidence coming from CDP-choline and alpha-GPC in middle-aged and older adults. Choline bitartrate and choline chloride have not demonstrated consistent cognitive benefits.

Middle-Aged and Older Adults

CDP-choline for short-term recall (1996). A study among older men and women (average age 67) showed that 1,000 mg of CDP-choline twice daily for 2 months modestly improved short-term recall compared to placebo [37].

CDP-choline for attention in middle-aged women (2012). A study among healthy middle-aged women (average age 47) given either 250 mg or 500 mg of CDP-choline (Cognizin) daily for one month modestly improved certain measures of attention compared to placebo. Interestingly, those taking the lower dose had slightly better results than those taking the higher dose [38].

CDP-choline for visual memory (2021). A study among 99 healthy adults (average age 64) found that 500 mg of CDP-choline (Cognizin) taken once daily with breakfast for three months did not improve working memory or five of seven other cognitive measures, including attention. However, those who took CDP-choline did have modest, statistically significant improvements in visual memory, new learning (Paired Associate test), and composite memory scores [39]. The study was funded by the maker of Cognizin.

Choline chloride for memory in elderly (1980). A small study among elderly adults given 2,000 mg of choline chloride four times daily for 21 days found no improvement in memory compared to placebo [40].

Choline bitartrate with caffeine (2013). A single 2,000 mg dose of choline bitartrate taken with 25 mg of caffeine improved short-term memory and attention in middle-aged adults 40 minutes after ingestion compared to caffeine alone or placebo. However, there was no benefit when taking choline bitartrate with greater amounts of caffeine (50 mg or 100 mg) or when taking choline bitartrate alone [41].

Younger People

Choline bitartrate in young adults (2016). A single dose of choline bitartrate had no memory benefit in young adults one to two hours after ingestion [42].

Egg-based choline in preadolescents (2022). A study among 122 preadolescents (average age 11) showed that replacing snacks or meals with foods containing whole egg powder in amounts providing 241 mg of choline per day for 9 months did not improve cognitive measures, including executive function, processing speed, or memory, compared to placebo. Low adherence may have contributed to the lack of benefit [43].

Attention in Adolescents

CDP-choline in male adolescents (2015). A study among 75 healthy male adolescents (ages 13 to 18) who took either 250 mg or 500 mg of CDP-choline once daily for one month had slightly improved measures of attention, psychomotor speed, and reduced impulsivity compared to placebo [44].

Observational Data on Choline and Cognition

Higher choline intakes and plasma concentrations have been associated with better cognitive performance in several observational studies:

• In 2,195 adults aged 70–74 in Norway, those with plasma free choline concentrations below 8.4 micromol/L (20th percentile) had poorer sensorimotor speed, perceptual speed, executive function, and global cognition compared to those above this threshold [45].
• In 1,391 adults aged 36–83 from the Framingham Offspring study, higher choline intakes were associated with better verbal memory and visual memory. Higher choline intakes during the earlier assessment period were also associated with smaller white matter hyperintensity volume — a sign of small-vessel disease in the brain [46].

However, a 2015 systematic review of 13 studies on choline levels and neurological outcomes in adults found that choline supplements did not result in clear improvements in cognition in healthy adults [47].

Alzheimer's Disease and Dementia

Egg consumption and Alzheimer's risk. A study among 1,024 older adults (average age 82) living in a retirement community found those who consumed at least one egg per week were 47% less likely to be diagnosed with Alzheimer's disease over a 7-year follow-up compared to those who consumed less than one egg per week. Notably, 83% of those studied carried the ApoE-ε4 allele — the strongest predictor of late-onset Alzheimer's disease. Among those who did develop Alzheimer's, consuming more than 2 eggs per week was associated with 34% longer time to diagnosis [48].

Lecithin for Alzheimer's disease. High daily doses of lecithin (20 to 30 grams per day) have generally not been found to be beneficial in people with Alzheimer's disease [49][50]. A 2003 Cochrane Review of 12 randomized trials in 265 patients with Alzheimer's disease, 21 with Parkinsonian dementia, and 90 with self-identified memory problems found no clear clinical benefits of lecithin supplementation [51].

Alpha-GPC for Alzheimer's disease. A study among 261 men and women (ages 60 to 80) with mild to moderate probable or possible Alzheimer's disease found that 400 mg of alpha-GPC taken three times daily (total daily dose of 1,200 mg alpha-GPC) for six months modestly improved cognition and global function compared to placebo [52].

The same daily dose (1,200 mg alpha-GPC) taken with 10 mg of donepezil (Aricept) for 2 years decreased depression, anxiety, and apathy in patients with mild to moderate Alzheimer's disease, while donepezil with placebo increased the severity and frequency of these symptoms. The combination also significantly decreased severity and stress of patients' caregivers compared to donepezil with placebo [53].

Subgroup analyses in an open-label trial of alpha-GPC (1,200 mg/day for 3 months) in 50 patients with amnestic mild cognitive impairment indicated that cognitive improvements were more pronounced in non-carriers of the APOE-ε4 allele compared to carriers [54].

CDP-choline with cholinesterase inhibitors. A study in Italy found that 1,000 mg of CDP-choline taken with either donepezil (Aricept), rivastigmine (Exelon), or galantamine (Razadyne) for nine months resulted in modest improvements in cognition compared to drug treatment alone [55]. There is also evidence that 1,000 mg of CDP-choline taken with galantamine may slow the progression of Alzheimer's disease compared to galantamine alone [56].

Parkinson's Disease

A study in China among 81 adults with Parkinson's disease and mild cognitive impairment showed that taking 200 mg of CDP-choline sodium three times daily for 18 months as add-on to standard Parkinson's medication modestly slowed decline in cognition compared to medication plus placebo. Those in the CDP-choline group showed a decline in cognition of 0.91 points (out of 30) compared to a 2.4-point decline in the placebo group [57].

Pregnancy and Lactation

Choline plays critical roles in fetal brain and memory development and appears to decrease the risk of neural tube defects, similar to folate [9][10]. In June 2017, delegates at the American Medical Association annual meeting voted to support evidence-based amounts of choline in all prenatal vitamins, noting that most prenatals currently contain little if any choline [17].

Maternal supplementation and infant brain development. A study of 24 women entering the third trimester of pregnancy provided either 100 mg or 550 mg of choline daily in addition to 380 mg of choline from their diet (total daily intake of 480 mg or 930 mg respectively), along with vitamins, minerals, and 200 mg of DHA. When tested at 4 through 13 months of age, infants whose mothers had taken the higher choline dose had significantly faster information processing speeds [58].

Long-term effects on attention. A follow-up analysis of 20 children from the study above found that, at age 7, children of mothers with the higher daily intake of choline during the third trimester scored significantly higher on a test of sustained attention (0.71 vs 0.46 on the Sustained Attention Task test, scale of −1 to +1) [59].

Neural tube defect risk. Some evidence indicates that lower plasma or serum choline levels during pregnancy are associated with an increased risk of neural tube defects [60][61]. However, other research found no relationship between plasma choline concentrations during pregnancy and neural tube defects in offspring [62].

Practical guidance. The AI for choline is 450 mg during pregnancy and 550 mg during lactation. Given that young women consume on average only 280 mg of choline per day, supplementing with approximately 200–400 mg daily during pregnancy and 300–600 mg during the third trimester and lactation would seem appropriate, depending on dietary intake [17].

Physical Performance

A small study among healthy college-age men (average age 21) found that 600 mg of alpha-GPC for 6 days increased lower body isometric muscle strength but did not increase upper body muscle strength compared to placebo [63]. However, another small study in healthy men found no improvement in physical or cognitive performance after exhaustive physical activity following a dose of choline (50 mg per kg of body weight) [64].

Breast Cancer

A study among 3,000 US women found that breast cancer risk was reduced 24% among women with a high dietary intake of choline (greater than 488 mg/day). However, risk was increased 30% among women homozygous for the minor allele of PEMT rs12325817, a gene variant that increases dietary choline requirements [65]. There do not appear to be clinical trials investigating choline supplementation and breast cancer risk.

Asthma

A study in India found that, compared to placebo, a dose of either 500 mg or 1,000 mg of choline citrate taken three times daily decreased symptoms and increased the number of asymptomatic days in patients with asthma. Those taking the higher dose also had a decreased need for asthma medication [66].

Another study in India found that 1,500 mg of choline chloride taken twice daily, in addition to standard medications for six months, slightly improved bronchial reactivity and certain measures of immune inflammation and reduced medication use, but did not decrease overall symptoms compared to standard medication alone [67].

Ulcerative Colitis

People with ulcerative colitis may have insufficient amounts of phosphatidylcholine in the mucus lining of the colon; mucus phosphatidylcholine content may be reduced by as much as 70% [68].

Mixed results. A study among 156 people with ulcerative colitis with inadequate response to mesalazine found that 3.2 grams of a delayed-release formula of soy lecithin containing greater than 94% phosphatidylcholine produced no difference in remission rate compared to placebo, although there was a greater reduction in disease activity (51.7% versus 33.3%) [69]. A similar study in Spain was terminated in 2017 after showing no benefit [70].

Earlier positive results. An analysis of data from three earlier studies at a single clinic in Germany (2005–2010) showed 49% of those receiving phosphatidylcholine achieving remission versus only 9% receiving placebo [71].

Glaucoma

There is preliminary evidence that citicoline (1,000 mg per day) may help slow the progression of primary open angle glaucoma [72].

Dry Eye

Although choline deficiency has been linked with dry eye and phosphatidylcholine is a key component of tears, a study among 20 adults with dry eye disease showed that taking 4,800 mg of sunflower lecithin daily for about 13 weeks did not significantly reduce self-reported dry eye compared to placebo [73].

Recommended Dosing

Adequate Intakes (AI)

The Institute of Medicine established AIs for choline in 1998, based on the prevention of liver damage [2]:

Age / Group	AI (mg/day)
Infants 0–6 months	125
Infants 7–12 months	150
Children 1–3 years	200
Children 4–8 years	250
Children 9–13 years	375
Males 14+ years	550
Females 14–18 years	400
Females 19+ years	425
Pregnant women	450
Lactating women	550

Tolerable Upper Intake Levels (UL)

Age	UL (mg/day)
Children 1–8 years	1,000
Children 9–13 years	2,000
Adolescents 14–18 years	3,000
Adults 19+ years	3,500

Note that the European Food Safety Authority (EFSA) did not establish an upper tolerable intake level for choline in its 2016 scientific opinion due to insufficient data [74].

Dosing by Condition

The following dosing recommendations are based on clinical trial evidence:

• For stroke: 2,000 mg of CDP-choline within 24 hours of onset [36].
• For memory and cognition: 250–500 mg of CDP-choline daily for attention [38]; 1,000 mg of CDP-choline daily for short-term recall in older adults [37]; 500 mg daily for visual memory [39].
• For Alzheimer's disease: 400 mg of alpha-GPC three times daily (1,200 mg/day) [52]; 1,000 mg CDP-choline daily as adjunct to cholinesterase inhibitors [55].
• For attention in adolescents: 250–500 mg of CDP-choline once daily [44].
• For Parkinson's disease: 200 mg of CDP-choline sodium three times daily (600 mg/day) [57].
• For asthma: 500–1,000 mg of choline citrate three times daily [66].
• For pregnancy: 200–400 mg daily; 300–600 mg during the third trimester and lactation [17].
• For glaucoma: 1,000 mg of citicoline per day (preliminary evidence) [72].

How to Read a Supplement Label

The weight of the choline compound and the weight of actual choline are different. Most supplements list the amount of ingredient, not the amount of choline:

• 1,000 mg choline bitartrate = 411 mg choline
• 1,000 mg alpha-GPC = 403 mg choline
• 1,000 mg CDP-choline (citicoline) = 214 mg choline
• 1,000 mg phosphatidylcholine = 137 mg choline
• 4,000 mg lecithin = approximately 134 mg choline

Safety and Side Effects

Common Side Effects

Intake of choline is generally considered safe up to the Tolerable Upper Intake Level (UL) of 3,500 mg per day for adults [2][17]. At high dosages, gastrointestinal side effects may occur, including abdominal discomfort, diarrhea, and nausea.

Fishy body odor. Choline may lead to a fishy body odor in as much as 1% of the US population who have a genetic defect in the FMO3 gene, which impairs trimethylamine metabolism. A choline-restricted diet diminishes body odor in this population [75].

Other reported side effects at high doses include vomiting, excessive sweating and salivation, and hypotension [1][2].

TMAO and Cardiovascular Risk

The most significant safety concern with choline supplementation relates to TMAO (trimethylamine N-oxide), a compound produced when gut bacteria convert choline to TMA, which is then oxidized to TMAO in the liver. TMAO may advance atherosclerosis by reducing normal cholesterol clearing and has been associated with increased instability of atherosclerotic plaque [76].

TMAO and cardiovascular events. A 3-year study showed that people with the highest blood plasma levels of TMAO were 2.5 times as likely as those with the lowest levels to suffer a heart attack or other major adverse cardiovascular event [77].

Choline bitartrate significantly raises TMAO. A Cleveland Clinic study found that choline bitartrate supplementation (411 mg/day total choline) for one month increased fasting TMAO levels by about 71% and increased platelet aggregation [18]. Another study found that 450 mg of choline from choline bitartrate twice daily increased TMAO levels more than 10-fold in vegans/vegetarians and 14-fold in omnivores over 1–2 months. Daily aspirin (81 mg) was able to reduce but not eliminate the increase in platelet aggregation [19].

Phosphatidylcholine does NOT raise TMAO. The Cleveland Clinic study found that phosphatidylcholine supplementation (410 mg total choline) for one month did not increase fasting TMAO levels [18]. A meal study among 37 healthy men confirmed this: blood and urinary TMAO levels were 295% and 250% higher after a meal containing 600 mg of free choline as choline bitartrate compared to control, while phosphatidylcholine and control meals produced no difference [27].

Eggs and TMAO. While eating eggs can temporarily increase TMAO levels — from about 4 micromol to close to 8 micromol at one hour after intake — levels return to normal after about two hours, and fasting TMAO levels do not appear to be elevated [77]. A study in 69 healthy young adults confirmed that eating 1 or 2 eggs per day for several weeks did not affect fasting TMAO levels [78]. The Cleveland Clinic study also found that consuming 4 eggs daily for one month did not increase fasting TMAO [18].

Alpha-GPC and Stroke Risk

A large observational study followed 12 million adults (average age 62) in South Korea and found that those who had been prescribed alpha-GPC for any duration over the 3 years prior to the study had a 46% higher risk of total stroke over the subsequent 10 years compared to non-users. Among users, stroke risk was dose-dependent: increased by 10% for 2–6 months of use, 15% for 6–12 months, and 37% for more than 12 months compared to those using alpha-GPC for less than 2 months [22]. Higher TMAO levels have been linked with increased stroke risk in other observational research [79].

Until more is known, it may be prudent to avoid regular, long-term use of alpha-GPC, especially among people at risk of adverse cardiovascular events.

Choline and Mortality

Higher dietary intake of choline (averaging 364 mg daily) was associated with a 23% greater risk of death and a 33% greater risk of death from cardiovascular disease compared to lower intakes (averaging 206 mg daily), in a study that followed over 20,000 US adults for an average of 30 years [80]. However, the "higher" intake level in this study is actually below the AI for choline. This study shows only an association — not a cause-and-effect relationship.

Several large observational studies have found no significant associations between choline intakes and cardiovascular disease risk. An analysis of 72,348 women and 44,504 men showed no association between choline intake and peripheral artery disease risk [81]. A 14-year prospective study of 14,430 middle-aged adults found no significant difference in coronary heart disease risk across choline intake quartiles [82]. Choline intakes also had no association with cardiovascular disease risk in 16,165 women in the European Prospective Investigation into Cancer and Nutrition [83].

Eggs and Cardiovascular Risk

A study that followed 96,831 postmenopausal women over approximately 17 years found that consuming one or more eggs per day was associated with a 14% increased risk of heart attack, ischemic stroke, heart failure, or death from cardiovascular disease, compared to consuming less than one egg per week [84]. An observational study of nearly 4,000 adults with pre-existing coronary heart disease found that eating between one and two eggs per day increased mortality risk by 31% compared to eating no eggs [85].

Kidney Stones

Choline bitartrate may, in large doses, lead to an unusual type of kidney stone made of crystals of calcium tartrate tetrahydrate. This was reported in three men who each consumed several servings daily of an energy supplement containing 500 mg of "choline (as bitartrate or citrate)" per serving for a year or more. Most of the choline bitartrate molecule is tartaric acid, providing the building block for these crystals [24].

Cancer Risk

Colorectal cancer. A population study found an association between higher intakes of choline and higher risks of colorectal cancer in women, although it was not clear if this was due to choline or other components in the foods [86].

Prostate cancer. Evidence is conflicting. One population study suggested an association between higher dietary choline intake and risk of lethal prostate cancer [87], while a later study did not find this association [88].

Drug Interactions

Choline is not known to have any clinically relevant interactions with medications according to the NIH Office of Dietary Supplements [2]. However, some potential interactions warrant consideration:

• Cholinesterase inhibitors (donepezil, rivastigmine, galantamine): Choline supplements, particularly alpha-GPC and citicoline, may enhance the effects of these drugs by further increasing acetylcholine levels. While this may amplify cognitive benefits, it could also raise the risk of cholinergic overload in sensitive patients [52][53][55][89].
• Anticholinergic medications: Choline supplements may theoretically counteract the effects of anticholinergic drugs by increasing acetylcholine availability, though clinical evidence is limited [5].
• Methotrexate: Methotrexate inhibits dihydrofolate reductase, which can increase the need for choline as a methyl donor when folate pathways are impaired [1].

Patients on any of these medications should consult their healthcare provider before starting choline supplements.

Dietary Sources

Many foods contain choline. The main dietary sources in the United States consist primarily of animal-based products — meat, poultry, fish, dairy products, and eggs. Cruciferous vegetables and certain beans are also rich in choline, and other sources include nuts, seeds, and whole grains [4][15].

Top Food Sources

Food	Serving	Choline (mg)	% DV (550 mg)
Beef liver, pan fried	3 ounces	356	65%
Whole eggs	1 large, hard boiled	147	27%
Beef top round, braised	3 ounces	117	21%
Soybeans, roasted	1/2 cup	107	19%
Chicken breast, roasted	3 ounces	72	13%
Beef, ground, 93% lean	3 ounces	72	13%
Cod, Atlantic, cooked	3 ounces	71	13%
Red potato, baked	1 large	57	10%
Wheat germ, toasted	1 ounce	51	9%
Kidney beans, canned	1/2 cup	45	8%
Quinoa, cooked	1 cup	43	8%
Milk, 1% fat	1 cup	43	8%
Brussels sprouts, boiled	1/2 cup	32	6%
Broccoli, chopped, boiled	1/2 cup	31	6%
Peanuts, dry roasted	1/4 cup	24	4%
Cauliflower, boiled	1/2 cup	24	4%
Dark chocolate	100 g	46	8%

Sources: USDA FoodData Central [90]; USDA Database for the Choline Content of Common Foods [91].

Practical Notes on Dietary Choline

• Eggs are the richest common food source. All of the choline in an egg is in the yolk — egg whites contain none [17][91].
• Organ meats are exceptionally rich. Beef liver provides approximately 356 mg per 3-ounce serving [90].
• Phosphatidylcholine from food is better absorbed than choline bitartrate supplements. A study showed 4-fold greater absorption from egg yolk phospholipids compared to choline bitartrate [25].
• Choline and folate share methyl-donor functions. When dietary folate is deficient, choline becomes the primary methyl donor, increasing the need for dietary choline [1]. Conversely, adequate folate intake may partially compensate for low choline intake.
• Cooking does not substantially destroy choline. Unlike some heat-sensitive vitamins, choline is relatively stable during cooking, though some leaching into cooking water can occur.
• A Mediterranean or vegetarian diet is reported to help reduce TMAO levels, which may mitigate cardiovascular concerns associated with choline intake [92].

References

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