Choline is an often-overlooked nutrient — so overlooked that it wasn’t until 1998 that the Institute of Medicine officially recognized it as an essential nutrient.1 Choline has many roles in human metabolism and is involved in everything from cell structure to the synthesis of neurotransmitters.

Choline is necessary for cell-membrane signaling, the transport of lipids and methyl-group metabolism, which is involved in detoxification. During development, choline is essential for the brain and memory in the fetus and decreases the risk of neural tube defects.2

A deficiency in choline may contribute to liver disease, atherosclerosis and neurological disorders, and its importance continues through adulthood and into old age.

While choline is found in a variety of foods, intakes for adults and children are believed to be far below optimal levels, putting public health at risk and leading experts to suggest that [intake of choline-rich foods should be encouraged.3 Among them, krill oil may be superior, due to its unique phospholipids.4

Why Krill Oil Is an Ideal Source of Choline

Norwegian researchers conducted a study looking into the use of phosphatidylcholine from krill oil to counteract the drop in choline that often occurs among athletes competing in triathlons. Choline plays a role in normal muscle function, and it’s known that the concentration of free choline may decrease during long distance high-intensity exercise.5

Krill oil contains 69 choline-containing phospholipids to synthesize phosphatidylcholine, a critical component of human cell membranes.6 This is key to its benefits as a source of choline, because it’s estimated that 60% of choline in organic salts is otherwise lost when gut bacteria convert it to the metabolite trimethylamine (TMA).

Enzymes may then turn TMA into trimethylamine-N-oxide (TMAO), a potential biomarker for insulin resistance and heart problems. Krill oil, however, contains fatty acids in the form of phosphatidylcholine (PC) — unlike fish oil, which contains them in triglyceride form.

As noted by the researchers, “Choline in the form of PC is considerably less converted to TMA as demonstrated in a single-dose study with krill oil,7 potentially resulting in more efficient delivery of choline.”8 It’s been shown for instance, that 28 days of krill oil supplementation increased choline levels in healthy young adults.9

Krill Oil May Protect Choline Status in Athletes

Writing in the journal Frontiers in Nutrition, researchers set out to determine if supplementing with phosphatidylcholine from krill oil prior to a triathlon would counteract the expected drop in choline during the race.10 For the study, 24 athletes received either 4 grams of krill oil or 4 grams of mixed vegetable oil daily for five weeks prior to the race.

Blood samples to assess choline and its metabolites were taken before, immediately after and the day after the race. Choline concentrations significantly declined from before the race to after among the athletes, but those in the krill oil group had significantly higher concentrations of choline compared to the vegetable oil group, and also had a significantly greater increase in choline after the race was completed.

“In conclusion,” the researchers noted, “krill oil may help to prevent that circulating choline concentrations become limiting during endurance competitions.”11 However, it’s not only athletes who may benefit from the choline krill oil provides, especially considering that a National Health and Nutrition Examination Survey found that 90% of the U.S. population had inadequate choline intake.12

Risks of Choline Deficiency

Choline is a nutrient that’s important throughout life. Among adults deprived of choline, 77% of men and 80% of postmenopausal women developed fatty liver or muscle damage — signs of organ dysfunction — as did 44% of premenopausal women.13 When incremental amounts of choline were added back into their diets, normal organ function was restored. As noted by researchers in the journal Nutrition Reviews:14

“Because of its wide-ranging role in human metabolism, from cell structure to neurotransmitter synthesis, choline deficiency is now thought to have an impact on diseases such as nonalcoholic fatty liver disease, atherosclerosis (via lipoprotein secretion), and possibly neurological disorders. Therefore, getting adequate choline in the diet is important throughout life for optimal health.”

Some of the symptoms associated with low choline levels include memory problems, lethargy and persistent brain fog. Choline also prevents the buildup of homocysteine in your blood, which is important since elevated levels are linked to heart disease, cancer, cognitive decline and bone fractures.15

Choline also reduces chronic inflammation, and research shows that people with choline-rich diets have lower levels of inflammatory markers such as C-reactive protein, homocysteine, interleukin-6 and tumor necrosis factor.16 Meanwhile, choline deficiency is linked with DNA damage and apoptosis, and breast cancer risk may be reduced by 24% among women who eat a high-choline diet.17

Choline for Brain and Liver Health

Choline has also been implicated in the risk of dementia,18 may improve cognitive performance19 and low levels are associated with increased anxiety levels.20 It’s believed that choline may help to support the structural integrity of neurons, benefitting brain function in the elderly, and may even reduce the progression of dementia in people with Alzheimer’s disease.21

Further, without choline a range of your body’s metabolic processes will be seriously affected. According to the U.S. National Institutes of Health:22

“The body needs choline to synthesize phosphatidylcholine and sphingomyelin, two major phospholipids vital for cell membranes. Therefore, all plant and animal cells need choline to preserve their structural integrity.

In addition, choline is needed to produce acetylcholine, an important neurotransmitter for memory, mood, muscle control, and other brain and nervous system functions. Choline also plays important roles in modulating gene expression, cell membrane signaling, lipid transport and metabolism, and early brain development.”

A deficiency in choline can also lead to liver damage, including nonalcoholic fatty liver disease (NAFLD or hepatosteatosis). Because choline is involved in fat metabolism, low levels of the nutrient can result in an overaccumulation of deposits of fat in your liver.23

Not only have studies found that risk of NAFLD increases with lower dietary choline intake, but the risk of NAFLD was found to be 32% lower in women, and 25% lower in men, with the highest choline intakes compared to those with the lowest.24

Are You Getting Enough Choline?

A Dietary Reference Intake (DRI) has not been established for choline, but the Institute of Medicine set an adequate daily intake value for men, women and children. The daily values are 425 milligrams (mg) per day for women, 550 mg for men and 250 mg for children as a minimum amount to prevent choline deficiency and potential organ damage.

However, requirements may vary depending on your overall diet, genetic makeup and other lifestyle factors. Groups at particularly high risk for choline deficiency include pregnant mothers, endurance athletes, postmenopausal women, vegans and those who consume high amounts of alcohol. Here’s a further breakdown from the National Institutes of Health:25

AgeMaleFemalePregnant WomenNursing Women

0 to 6 months

125 mg/day

125 mg/day

7 to 12 months

150 mg/day

150 mg/day

1 to 3 years

200 mg/day

200 mg/day

4 to 8 years

250 mg/day

250 mg/day

9 to 13 years

375 mg/day

375 mg/day

14 to 18 years

550 mg/day

400 mg/day

450 mg/day

550 mg/day

19 years and older

550 mg/day

425 mg/day

450 mg/day

550 mg/day

While your liver makes a small amount of choline naturally, the amount it synthesizes is not enough to meet your body’s needs. This means you’ll need to consume it via your diet regularly.

Krill and Other Dietary Sources of Choline

According to a study published in the journal Nutrients, only 8.03% of U.S. adults are getting enough choline (including only 8.51% of pregnant women).26 Krill oil is a simple solution, which can boost choline levels after a single dose.27

In a study comparing phosphatidylcholine, present in krill oil, and choline bitartrate salt, it was found that the krill oil led to higher levels of the important metabolites betaine and dimethylglycine (DMG) along with lower levels of TMAO, which can lead to health issues, compared to the other choline source. Researchers explained:28

“Krill oil is increasingly recognized as a useful source of phosphatidylcholine, in addition to its acknowledged role in providing the omega-3 fatty acids EPA and DHA. In a former study, phosphatidylcholine was shown to raise plasma choline levels more efficiently compared to ingestion of free choline as choline chloride.”

Aside from krill oil, eggs — particularly the yolks — are another excellent choline source. Among egg consumers, more than 57% met the adequate intake levels for choline, compared to just 2.4% of people who consumed no eggs.29

In fact, the researchers concluded that it’s “extremely difficult” to get enough choline unless you eat eggs or take a dietary supplement, though it’s preferable to get nutrients from dietary sources whenever possible.30 Other dietary sources of choline include:31

Grass fed beef liver

Organic pasture raised chicken

Atlantic cod

Alaskan salmon

Kidney beans


Brussels sprouts


Shitake mushroom


Krill oil also offers additional nutrients alongside choline — another reason why it’s a great choice. In addition to choline, krill provides eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which are beneficial for heart health and have been shown to improve blood pressure,32 reduce overall inflammation, reduce the effects of rheumatoid arthritis33 and depression34 and help slow the progression of Alzheimer’s disease.35

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