Choline is a recently discovered nutrient.
It was only acknowledged as a required nutrient by the Institute of Medicine in 1998.
Although your body makes some, you need to get choline from your diet to avoid a deficiency.
However, less than 10% of the US population seems to be getting enough of this nutrient (1).
Here is everything you need to know about choline, including what it is and why you need it.
What Is Choline?
Choline is an essential nutrient (2).
This means it's required for normal bodily function and human health. Although small amounts of it can be made in the liver, the majority must be obtained from the diet.
Choline is an organic, water-soluble compound. It is classified as neither a vitamin nor a mineral.
However, it is often grouped with the vitamin B complex due to its similar properties and functions. In fact, this nutrient affects a number of vital bodily functions.
These include liver function, healthy brain development, muscle movement, the nervous system and metabolism, among others.
Therefore, adequate amounts are needed for optimal health and to reduce the risk of certain diseases (1).
Bottom Line: Choline is an essential nutrient that must be included in the diet to maintain optimal human health.
Choline Serves Many Functions in the Body
Choline plays an important part in many processes throughout the body.
These include the following key functions:
- Cell structure: It is needed to make fats that support the structural integrity of cell membranes (3).
- Cell messaging: It is involved in the production of compounds that act as cell messengers.
- Fat transport and metabolism: It is essential for making a substance required for transporting cholesterol from the liver. Inadequate choline may result in fat and cholesterol accumulating in the liver (4, 5).
- DNA synthesis: Choline and other vitamins such as B12 and folate help with a process that's important for DNA synthesis.
- A healthy nervous system: This nutrient is required to make acetylcholine, an important neurotransmitter. It's involved in memory, muscle movement, regulating heartbeat and many other basic functions.
Bottom Line: Choline is involved in many different processes. These include cell structure and messaging, fat transport and metabolism, DNA synthesis and the nervous system.
How Much Do You Need?
In order to get enough choline, you need to obtain it from your diet. Yet due to a lack of available evidence, a Reference Daily Intake (RDI) value has not been set.
However, the Institute of Medicine has set a value for adequate intake (AI) (6).
This value is intended to be sufficient for most healthy people, helping them avoid negative consequences of deficiency such as liver damage.
In addition, determining how much choline a person consumes is difficult due to limited knowledge about the amounts present in different foods.
Here are the recommended AI values of choline for different groups (10):
- 0–6 months: 125 mg per day.
- 7–12 months: 150 mg per day.
- 1–3 years: 200 mg per day.
- 4–8 years: 250 mg per day.
- 9–13 years: 375 mg per day.
- 14–18 years, female: 400 mg per day.
- 14–19 years, male: 550 mg per day.
- Adult women: 425 mg per day.
- Adult men: 550 mg per day.
- Breastfeeding women: 550 mg per day.
- Pregnant women: 450 mg per day.
It is important to note that many people do fine with less choline, while others need even more (2).
In one study of 26 men, six developed symptoms of choline deficiency even when consuming the AI amount (9).
Bottom Line: The adequate intake of choline is 425 mg per day for women and 550 mg per day for men. However, requirements vary by individual.
Choline Deficiency Is Unhealthy, But Rare
Choline deficiency can cause harm, especially for the liver.
One small study of 57 adults examined the effects of a choline-deficient diet.
Another study found that when postmenopausal women consumed a diet deficient in choline, 73% developed liver or muscle damage (12).
However, these symptoms disappeared once they began getting enough choline.
Choline is especially important during pregnancy, as a low intake may raise the risk of neural tube defects in unborn babies.
One study found that a higher dietary intake around the time of conception was associated with a lower risk of neural tube defects (13).
In addition, low choline intake may raise the risk of other pregnancy complications. These include preeclampsia, premature birth and low birth weight (2).
Additionally, it should be noted that although most Americans do not consume adequate amounts in their diets, actual deficiency is rare.
Bottom Line: Choline deficiency is associated with liver and/or muscle damage. Low intake during pregnancy is linked to complications.
Some People Are at Risk of Deficiency
Although choline deficiency is rare, certain people are at an increased risk (14):
- Endurance athletes: Levels fall during long endurance exercises, such as marathons. It's unclear if taking supplements improves performance (15, 16).
- High alcohol intake: Alcohol can increase requirements and the risk of deficiency, especially when intake is low (17, 18).
- Postmenopausal women: The hormone estrogen helps produce choline in the body. Since estrogen levels tend to drop in postmenopausal women, they may be at greater risk of deficiency (6, 19).
- Pregnant women: Requirements increase during pregnancy. This is most likely due to the unborn baby requiring choline for development (20).
Bottom Line: People who are at an increased risk of deficiency include athletes, those who drink a lot of alcohol, postmenopausal women and pregnant women.
Top Dietary Sources of Choline
Choline can be obtained from a variety of foods and supplements.
Dietary sources are generally in the form of phosphatidylcholine from lecithin, a type of fat.
- Beef liver: 1 slice (2.4 oz or 68 grams) contains 290 mg.
- Chicken liver: 1 slice (2.4 oz or 68 grams) contains 222 mg.
- Eggs: 1 large hard-boiled egg contains 113 mg.
- Fresh cod: 3 oz (85 grams) contain 248 mg.
- Salmon: A 3.9-oz (110-gram) fillet contains 62.7 mg.
- Cauliflower: 1 half cup (118 ml) contains 24.2 mg.
- Broccoli: 1 half cup (118 ml) contains 31.3 mg.
- Soybean oil: 1 tablespoon (15 ml) contains 47.3 mg.
So a single egg supplies about 20–25% of your daily requirement, and two large eggs provide almost half of your daily requirement (22).
In addition, a single 3 oz (85 grams) serving of beef kidney or liver can supply all of a woman's daily requirement and most of a man's (23).
Bottom Line: Rich food sources include beef liver, eggs, fish, nuts and certain vegetables like cauliflower and broccoli.
Additives and Supplements
Soy lecithin is a widely used food additive that contains choline. Therefore, it is likely that some extra is consumed through the diet via food additives.
Lecithin can also be purchased as a supplement. However, lecithin tends to only contain 10–20% phosphatidylcholine.
Phosphatidylcholine can also be taken as a pill or powder supplement, yet choline comprises only about 13% of the weight of phosphatidylcholine (24).
Other forms of supplements include choline chloride, CDP-choline, alpha-GPC and betaine.
If you are looking for a supplement, CDP-choline and alpha-GPC tend to be higher in choline content per unit weight. They are also more easily absorbed than others.
Some sources claim that choline in nutritional supplements may reduce body fat, but there is little to no evidence supporting these claims.
Bottom Line: Choline can also be taken as a supplement. CDP-choline and alpha-GPC seem to be the best types.
Choline and Heart Health
Higher intakes of choline have been associated with a reduced risk of heart disease (25).Folate and choline are involved in the conversion of the amino acid homocysteine to methionine.
Therefore, a deficiency of either nutrient can result in an accumulation of homocysteine in the blood.
Elevated levels of homocysteine in the blood are associated with an increased risk of heart disease and strokes (26).
However, the evidence on this topic is mixed.
Bottom Line: Choline may help reduce the risk of heart disease by lowering homocysteine levels. However, the evidence is mixed.
Choline and the Brain
Choline is required to produce acetylcholine, a neurotransmitter that plays an important role in regulating memory, mood and intelligence (33).
It's also needed for the process that synthesizes DNA, which is important for brain function and development (34).
Therefore, it's not surprising that choline intake has been associated with improvements in brain function.
Memory and Brain Function
Supplementing with 1,000 mg per day led to improved short- and long-term memory in adults aged 50–85 who had poor memory (37).
In a 6-month study, giving phosphatidylcholine to people with early Alzheimer's disease modestly improved memory in one small subgroup (38).
Bottom Line: A higher choline intake has been associated with improved memory function in some studies, but the evidence is mixed.
However, there are only a few studies on this in humans.
One observational study of 1,210 pregnant women found choline intake had no links to mental performance in their children when they were 3 years old (44).
Nevertheless, the same study found that a higher intake during the second trimester was associated with better visual memory scores in the same children at age 7 (45).
Another study gave 99 pregnant women 750 mg of choline per day from when they were 18 weeks pregnant to three months after pregnancy. They found no benefits for brain function or memory (46).
Bottom Line: Animal studies show that choline supplements during pregnancy can improve brain development. However, the evidence in humans is limited.
Some evidence suggests choline may play a role in the development and treatment of certain mental health disorders.
One large observational study found that lower blood levels were associated with a higher risk of anxiety, but not depression (47).
These levels are also used as an indicator for certain mood disorders, and choline supplements are sometimes used to treat bipolar disorder (48).
One study found that choline therapy improved symptoms of mania in individuals diagnosed with bipolar disorder (49).
However, there are currently not many studies available on this.
Bottom Line: Choline may play a role in the treatment of disorders such as anxiety and bipolar disorder. However, more research is needed.
Other Health Benefits of Choline
Choline levels have been associated with the development and treatment of certain diseases.
However, for most of these, the relationship is not clear and research is ongoing (50).
Although choline deficiency results in liver disease, it's not clear whether intakes lower than the recommended levels lead to an increased risk of liver disease.
A study of more than 56,000 people found that normal-weight women with the highest intakes had a 28% lower risk of liver disease, compared to those with the lowest intakes (51).
The study found no association with liver disease in men or overweight women (51).
Another study of 664 people with non-alcoholic liver disease found that lower intakes were associated with greater disease severity (52).
Bottom Line: Limited evidence indicates that higher intakes of choline may reduce the risk or severity of liver disease in certain people.
One study involving 1,508 women found that those consuming diets high in free choline were 24% less likely to get breast cancer (55).
However, the evidence is mixed.
Bottom Line: The relationship between choline intake and cancer is not clear. In some cases, a higher intake may reduce the risk. For other cancers, a higher intake may increase the risk.
Neural Tube Defects
Higher intakes of choline during pregnancy may reduce the risk of neural tube defects in babies.
One study found that women who had higher intakes around conception had a 51% lower risk of neural tube defects, compared to women with very low intakes (61).
Another observational study found that pregnant women with the lowest intakes were more than twice as likely to have babies with neural tube defects (62).
Bottom Line: Some evidence suggests higher choline intake during pregnancy may reduce the risk of neural tube defects.
Too Much Can Be Harmful
Consuming too much choline has been associated with unpleasant and potentially harmful side effects.
These include drops in blood pressure, sweating, fishy body odor, diarrhea, nausea and vomiting.
The daily upper limit for adults is 3,500 mg per day. This is the highest level of intake that is unlikely to cause harm.
It is very unlikely that someone could ingest this amount from food alone. It would be almost impossible to reach this level without taking supplements in large doses.
Bottom Line: Consuming too much choline has been linked to unpleasant and potentially harmful side effects.
Take Home Message
Choline is an essential nutrient that is required for optimal human health.
It may play a key role in healthy brain function, heart health, liver function and pregnancy, to name a few.
Although actual deficiency is rare, most Western people do not consume enough.