Choline

How much you need

The official Adequate Intake for adults, per day:

These are Adequate Intakes, not Recommended Dietary Allowances — there was not enough evidence to set a requirement, so they are based on the amount that prevents liver damage. How much choline a person needs also depends on the methionine, betaine and folate in their diet, on sex, pregnancy and breastfeeding, and on genetic differences.

People aged 18 fall in the official 14–18 group — 550 mg a day for males and 400 mg for females, 450 mg in pregnancy and 550 mg when breastfeeding. Its upper limit is lower, at 3,000 mg. Pregnancy and breastfeeding change what you need — confirm yours with your midwife, obstetrician or doctor.

Upper limit

The upper limit covers choline from food and supplements combined. It is the most that is unlikely to cause harm, not a target, and was set from the amounts linked with low blood pressure and a fishy body odour. It does not apply to people taking high doses under medical supervision.

What it does

Choline is an essential nutrient and a source of the methyl groups many steps of metabolism need ^[1]. The body uses it to make phosphatidylcholine and sphingomyelin, two phospholipids vital for cell membranes, and acetylcholine, a neurotransmitter for memory, mood, muscle control and other brain and nerve functions ^[1]. It also plays roles in gene expression, cell signalling, fat transport and metabolism, and early brain development ^[1]. The liver makes some choline, but not enough to meet human needs, so some must come from the diet ^[1].

Forms

About half the choline Americans eat is phosphatidylcholine ^[1]. Lecithin, a substance rich in phosphatidylcholine, is a common additive in processed foods such as gravies, salad dressings and margarine ^[1]. Supplements contain choline bitartrate, phosphatidylcholine or lecithin, typically 10 to 250 mg, and no studies have compared how well each form is absorbed ^[1]. Precise figures for how much of each dietary form is absorbed are not available ^[1].

Where it comes from

1. Beef liver, pan fried3 ounces356 mg
2. Egg, hard boiled1 large147 mg
3. Beef top round, separable lean only, braised3 ounces117 mg
4. Soybeans, roasted½ cup107 mg
5. Chicken breast, roasted3 ounces72 mg

How these five were chosen: The five foods with the most choline per serving in the NIH fact sheet's food table. Fortified foods are marked.

In the United States

Most Americans eat less than the Adequate Intake: in national survey data from 2013–2014, average intake from food and drink was 402 mg a day for men and 278 mg for women ^[1]. Supplements add very little to total intake ^[1]. In 2007–2008 data, black males of all ages had lower average intakes than white and Hispanic males, while intakes did not differ much among women ^[1].

Who is most likely to run low

• Pregnant women — about 90% to 95% eat less than the Adequate Intake, and prenatal supplements typically contain little if any choline ^[1]
• People with genetic variants that raise their need for dietary choline, including one that blunts estrogen's effect on choline production in women ^[1]
• People who rely on total parenteral (intravenous) nutrition, because choline is not routinely added to the solutions ^[1]

What deficiency looks like

Choline deficiency can cause muscle damage, liver damage and nonalcoholic fatty liver disease ^[1]. Although most Americans eat less than the Adequate Intake, frank deficiency in healthy men and nonpregnant women is very rare, possibly because the body makes some choline itself ^[1]. In a study of 57 adults fed a diet with less than 10% of the Adequate Intake for up to 42 days, 37 developed liver dysfunction ^[1]. Choline status is not routinely measured in healthy people ^[1].

What the evidence supports, and what it doesn't

Established. Choline is needed for cell membranes and for moving fat out of the liver; without enough, fat builds up in the liver ^[1]. The Adequate Intakes are set at the amount that prevents liver damage, and the fact sheet states that adequate choline is needed for proper liver function and to prevent nonalcoholic fatty liver disease ^[1].

Not supported by trials. Cognition: a 2015 systematic review of 13 studies found that choline supplements did not clearly improve cognition in healthy adults, and a 2003 Cochrane review of 12 trials found no clear benefit of lecithin supplements in treating Alzheimer's disease or Parkinsonian dementia ^[1]. Heart disease: several large observational studies — including 72,348 women and 44,504 men in two U.S. cohorts — found no link between choline intake and cardiovascular or peripheral artery disease ^[1].

Mixed. A later analysis of 80,978 women and 39,434 men in the same U.S. cohorts found higher mortality among those eating the most choline; the authors suggested TMAO, a compound gut bacteria help make from choline and linked to heart disease, but did not measure it ^[1]. Observational studies in adults link higher choline intake or blood levels with better memory and cognition ^[1]. Fatty liver: a cross-sectional study of 56,195 Chinese adults found that those eating the most choline had a lower risk of nonalcoholic fatty liver disease — 32% lower in women and 25% lower in men — but only one large study supports the link, and more research is needed ^[1]. Pregnancy: some studies link lower choline levels with neural tube defects, but others found no relationship ^[1].

Too much

High intakes of choline are associated with a fishy body odour, vomiting, heavy sweating and salivation, low blood pressure and liver toxicity ^[1]. Eating more choline also increases production of TMAO, which has been linked to a higher risk of cardiovascular disease, in proportion to the dose ^[1].

Medicines that interact

Choline is not known to have any clinically relevant interactions with medicines ^[1]. If you take medicines regularly, your doctor or pharmacist can still tell you whether any supplement suits you.