Choline is a nutrient your body uses to build cell membranes and support brain function

Choline is a compound your body produces naturally, mostly in the liver, but you also get it from food. Your cells use it to build and maintain their outer membranes, and your brain uses it to make acetylcholine, a chemical messenger involved in memory and muscle control. Most people get some choline from eggs, chicken, beef, and certain vegetables, but some people take choline supplements because they believe they are not getting enough from diet alone or because they want to support specific functions like memory or athletic performance.

Choline is not a vitamin, though it is sometimes grouped with B vitamins because it works alongside them. Your body can manufacture choline on its own, which is why there is no official daily requirement the way there is for vitamin C. However, the National Academies of Sciences, Engineering, and Medicine has set an Adequate Intake level — a target amount that appears sufficient for most people — at 550 mg per day for adult men and 425 mg per day for adult women.

Key Takeaways

  • Choline supports cell membrane structure and the production of acetylcholine, a brain chemical involved in memory and muscle function.
  • Most people can get adequate choline from foods like eggs, chicken, and leafy greens, though some people take supplements if they believe their intake is low.
  • Research shows mixed results on whether choline supplements improve memory or athletic performance in people who already eat enough choline-rich foods.
  • Choline supplements come in several forms, including choline bitartrate, alpha-GPC, and CDP-choline, which differ in how your body absorbs and uses them.
  • High doses of choline can cause a fishy body odor, headaches, and digestive upset, and very high intakes may raise heart disease risk in some people.

What choline does in your body

Choline has two main jobs. First, it is a building block for phosphatidylcholine, a fat that makes up cell membranes throughout your body. Without enough choline, your cells cannot maintain their structure or function properly. Second, your brain uses choline to manufacture acetylcholine, the neurotransmitter that fires when you form memories, pay attention, or move your muscles. This is why choline is often marketed for brain health and athletic performance.

Choline also plays a role in fat metabolism — your liver uses it to package fat for transport through your bloodstream. Some research suggests that without adequate choline, fat can accumulate in the liver, though this is mainly a concern in people with very low intake or certain genetic conditions. Your body also uses choline to produce methyl groups, which are chemical units involved in DNA regulation and other cellular processes.

Common reasons people take choline supplements

People take choline supplements for several reasons, though the strength of evidence behind each varies. Some take it hoping to improve memory or mental clarity, since acetylcholine is involved in learning and attention. Others take it for athletic performance, based on the idea that more acetylcholine might improve muscle control or endurance. Pregnant women sometimes take choline because it is involved in fetal brain development, and some people take it to support liver health or to reduce fat buildup in the liver.

Older adults sometimes use choline supplements in hopes of slowing cognitive decline, though research on this is still developing. People with certain neurological conditions, like Alzheimer's disease, have been studied as potential users, but choline supplements are not a standard treatment. In all these cases, the evidence is stronger for people who are actually deficient in choline than for people who straightforward want to boost an already-adequate intake.

What research shows about choline supplement effects

Studies on choline supplements show a pattern: they appear to help people who are genuinely low in choline, but the benefit is less clear for people eating a normal diet. In people with adequate choline intake, taking more does not consistently improve memory, focus, or athletic performance in the way marketing sometimes suggests. Some studies show small improvements in memory tasks, while others show no difference between choline supplements and placebo.

Research on choline and athletic performance is limited. A few small studies suggest that choline might help with endurance or reduce fatigue during intense exercise, but the effect is modest and not seen in all studies. For cognitive decline in older adults, the evidence is mixed — some research suggests choline may slow decline in people at risk, but this is not yet proven enough to make it a standard recommendation. Pregnant women who take choline may support fetal brain development, and this is one area where the evidence is somewhat stronger, though more research is ongoing.

Different forms of choline supplements and how they work

Choline supplements come in several forms, and they differ in how your body absorbs and uses them. Choline bitartrate is the most common and least expensive form, but your body absorbs it less efficiently than other types. Alpha-GPC (alpha-glycerophosphocholine) is absorbed more readily and crosses into the brain more easily, which is why it is popular for cognitive and athletic purposes. CDP-choline (cytidine diphosphate choline) is another form that your body converts to choline and phosphatidylcholine.

Phosphatidylcholine is choline already bound to fat, which some people believe is absorbed better, though evidence on this is mixed. Choline citrate is another option. The form you choose matters somewhat — alpha-GPC and CDP-choline are more expensive but may be more effective for brain-related goals — but the most important factor is whether you actually need more choline in the first place. If your diet already contains adequate choline, switching to a premium form is unlikely to produce noticeable results.

Possible side effects and safety concerns

Choline supplements are generally well tolerated at moderate doses, but high intakes can cause side effects. The most common is a fishy body odor, which happens because excess choline is converted to trimethylamine, a compound with a distinctive smell. Headaches, nausea, diarrhea, and vomiting can occur at high doses. These side effects usually go away when you lower the dose or stop taking the supplement.

A more serious concern emerged from research suggesting that very high choline intake — well above the Adequate Intake level — may increase the risk of heart disease in some people, possibly by raising levels of trimethylamine-N-oxide, a compound linked to cardiovascular problems. This risk appears to be greatest in people who already have heart disease risk factors. The upper safe limit for choline is set at 3,500 mg per day for adults, but most people do not need anywhere near that amount. If you have heart disease, a family history of heart disease, or take blood thinners, talk with a doctor before starting a choline supplement.

How to know if you might need a choline supplement

True choline deficiency is rare in people eating a typical diet, but it can happen in people with certain conditions. Liver disease, kidney disease, and some genetic disorders can impair choline production or metabolism. People on parenteral nutrition (nutrition delivered intravenously) may need supplemental choline. Vegans and vegetarians sometimes have lower choline intake because eggs and meat are the richest sources, though plant sources like broccoli, Brussels sprouts, and soybeans contain meaningful amounts.

If you eat eggs regularly, you are likely getting adequate choline — one large egg contains about 147 mg. Chicken breast, beef, and fish are also good sources. If you are concerned about your intake, a food diary or conversation with a registered dietitian can help you figure out whether you actually need a supplement. Taking a supplement when you already have adequate intake is unlikely to produce the benefits marketing suggests, and it costs money without clear benefit.

Frequently Asked Questions

Does choline help with memory and focus?

Choline supports acetylcholine production, which is involved in memory and attention, so the logic makes sense. However, research shows that choline supplements improve memory mainly in people who are deficient. In people eating adequate choline from food, taking more does not consistently improve memory or focus. If you already eat eggs, meat, or leafy greens regularly, a supplement is unlikely to sharpen your thinking.

Can choline help with athletic performance?

Some small studies suggest choline might help with endurance or reduce fatigue during intense exercise, but the effect is modest and not consistent across all research. Most athletes do not need a choline supplement if they eat a balanced diet with adequate protein and whole foods. If you are interested in trying it, alpha-GPC is the form most studied for athletic purposes, but results are not may provide.

Is choline safe to take every day?

Choline is safe at the Adequate Intake level and below for most people. The upper safe limit is 3,500 mg per day, and most supplements contain far less. However, if you have heart disease, liver disease, or take blood thinners, talk with a doctor first. High doses can cause fishy body odor, headaches, and digestive upset, so start with a lower dose if you decide to supplement.

What foods have the most choline?

Eggs are the richest source — one large egg has about 147 mg. Beef, chicken, and fish contain 60 to 100 mg per serving. Plant sources include broccoli, Brussels sprouts, soybeans, and quinoa, though in smaller amounts. If you eat eggs and meat regularly, you are likely meeting the Adequate Intake without a supplement.

Do vegans need a choline supplement?

Vegans can get choline from plant sources like broccoli, Brussels sprouts, soybeans, and quinoa, but the amounts are smaller than in eggs and meat. Some vegans may benefit from a supplement or from eating more choline-rich plant foods. A registered dietitian can help you figure out whether your intake is adequate based on what you actually eat.