choline

Choline is an essential nutrient found in many foods and also sold as a dietary supplement (commonly as choline bitartrate, phosphatidylcholine, or lecithin). The body uses it to build the membranes that surround cells and to make acetylcholine, a neurotransmitter the brain and nervous system rely on for memory, mood, and muscle control; it also has roles in lipid transport, fat metabolism, and liver function. The liver can produce some choline on its own, but according to the NIH Office of Dietary Supplements that amount is not enough to meet the body's needs, so most choline has to come from the diet.

The NIH Office of Dietary Supplements (ODS) describes the research on choline as still developing rather than settled. For cognition, some studies link higher choline intake and higher blood choline levels to better memory, but other studies found that choline supplements did not improve cognition in healthy adults or in people with Alzheimer's disease, Parkinson's disease dementia, or other memory problems; ODS says more research is needed and does not establish a benefit for dementia. For heart health the evidence is genuinely mixed: some research suggests that getting enough choline may help keep the heart and blood vessels healthy, while other research suggests that higher amounts might raise cardiovascular disease risk, and ODS says more research is needed to know which way it goes. Adequate choline is needed for normal liver function and low intake is linked to nonalcoholic fatty liver disease (NAFLD), but ODS notes that more research is needed to understand whether choline can help prevent or treat it.

Recommended intakes are set as Adequate Intakes (AIs) rather than a full RDA, because the available evidence was not sufficient to set an RDA. The NIH lists 550 mg/day for adult men, 425 mg/day for adult women, 450 mg/day during pregnancy, and 550 mg/day while breastfeeding. Standalone supplements often supply far less than this, roughly 10 to 250 mg of choline per dose. Because individual needs vary with genetics, pregnancy, diet, and other factors, and because very high intakes can cause harm, talk to a doctor, pharmacist, or registered dietitian before starting a choline supplement.

Choline from a normal, varied diet is considered safe, and outright deficiency is uncommon in healthy people. To limit risk from high intakes, the NIH sets Tolerable Upper Intake Levels (ULs) that cover all sources combined—food, beverages, and supplements: 3,500 mg/day for adults and 3,000 mg/day for teens aged 14–18, with lower limits for younger children. ODS notes that some groups are more likely to have trouble getting enough choline, including people who are pregnant, people with certain genetic conditions, and people who are fed intravenously. Anyone who is pregnant or has a medical condition should check with a clinician before supplementing.

According to the NIH Office of Dietary Supplements, intakes above the upper limit can cause adverse effects, including a fishy body odor, nausea or vomiting, excessive sweating and salivation, drops in blood pressure, and liver damage. ODS also notes that some research suggests high amounts of choline may raise the risk of heart disease. These effects are associated with intakes that exceed the tolerable upper limit, not with the amounts found in a normal diet.

The NIH Office of Dietary Supplements states that choline is not known to interact with any medications. Even so, ODS advises telling your doctor, pharmacist, and other health care providers about every dietary supplement and prescription or over-the-counter medicine you take, so they can flag possible interactions and tell you whether a medicine might affect how your body absorbs, uses, or breaks down nutrients such as choline.