Standard fish oil supplements do not contain choline. The refining process used to produce fish oil specifically strips out phospholipids, which are the molecules that carry choline. So even though the raw fish tissue that oil comes from contains choline, the finished supplement in your softgel does not.
This distinction matters because choline and omega-3 fatty acids like DHA appear to work better together than either does alone. If you’re looking for both nutrients from a single source, you have options, but a regular fish oil capsule isn’t one of them.
Why Fish Oil Loses Its Choline
Choline exists in food primarily attached to phospholipids, a type of fat molecule that forms cell membranes. Whole fish like salmon contain meaningful amounts of choline because the flesh is full of intact cells with phospholipid membranes. But when manufacturers extract and purify fish oil, the very first step, called degumming, removes phospholipids along with trace metals and other impurities. What remains is a concentrated triglyceride oil rich in EPA and DHA but essentially free of choline.
After degumming, the oil goes through additional rounds of neutralization, bleaching, and steam distillation under vacuum. Each step further refines the product into a pure omega-3 oil. The result is effective for delivering EPA and DHA, but it’s a fundamentally different nutritional product than the whole fish it came from.
Krill Oil Is the Exception
Krill oil stands apart from standard fish oil because its omega-3 fats are bound to phospholipids rather than triglycerides. Roughly 34% of krill oil by weight is phosphatidylcholine, the phospholipid form of choline. In practical terms, a typical 2.5-gram daily dose of krill oil provides around 150 mg of choline alongside its EPA and DHA.
That 150 mg is a meaningful contribution but not enough on its own. The adequate daily intake for choline is 550 mg for men and 425 mg for women. So krill oil covers roughly 27% to 35% of your daily need, depending on sex, while also delivering omega-3s in a form that may be absorbed more efficiently. The phospholipid structure allows the fatty acids to be incorporated directly into cell membranes after absorption, rather than requiring the extra digestive steps that triglyceride-based fish oil needs.
Why Choline and Omega-3s Work Better Together
Choline and DHA have a cooperative relationship, particularly in the brain. Your body uses choline to build phosphatidylcholine, which serves as a transport vehicle that carries DHA into brain tissue. Without enough choline, DHA has a harder time reaching the cells that need it most.
Animal studies have shown this synergy in measurable terms. Combined supplementation of DHA and choline increased brain levels of a key DHA metabolite by 63% compared to controls, far more than either nutrient achieved alone. Animals receiving both nutrients together performed better on learning and memory tests, showing improved recognition of new objects and faster navigation of mazes. The combination appears to enhance synaptic function and raise levels of growth factors that support brain cell health.
Research in pregnant women found that supplementing DHA alongside 550 mg of choline during the third trimester boosted the liver’s ability to package and export DHA, increasing the supply available to the developing fetus. This suggests the pairing is especially relevant during pregnancy, when choline needs rise to 450 mg per day and fetal brain development demands large amounts of DHA.
How to Get Both Nutrients
If you’re currently taking standard fish oil and want choline too, you have a few practical paths. The simplest is to switch to krill oil, which naturally delivers both. You won’t get as much EPA and DHA per capsule as a concentrated fish oil, but you’ll get a built-in choline boost and potentially better absorption of the omega-3s you do get.
Another approach is to keep your fish oil and add choline separately. Choline supplements come in several forms, with choline bitartrate being the most common and affordable. You can also increase choline through food. Eggs are the richest common source, with a single large egg providing about 150 mg. Beef liver, soybeans, chicken, and cruciferous vegetables like broccoli are also significant contributors.
Most adults in the U.S. fall short of the recommended intake. The adequate intake of 550 mg for men and 425 mg for women is based on the amount needed to prevent liver damage, and many nutrition researchers consider it a floor rather than an optimal target. Tracking your intake for a few days using a food diary can reveal whether you’re in the gap.
Choosing the Right Supplement
If your primary goal is high-dose omega-3s for heart health or inflammation, concentrated fish oil remains the most efficient delivery method. Just know that you’ll need to get your choline elsewhere. If you’re more focused on cognitive support or are pregnant, krill oil’s natural combination of phospholipid-bound omega-3s and choline aligns well with the research on how these nutrients cooperate in the brain.
Some manufacturers now sell fish oil and choline as a combined formula, though these products simply add choline (usually as choline bitartrate) to standard triglyceride-based fish oil. There’s nothing wrong with this approach, but it’s not meaningfully different from taking two separate supplements. The choline in these products isn’t structurally bound to the omega-3 fats the way it is in krill oil, so you don’t get the same phospholipid-based absorption advantage.