The most reliable way to get DHA in your diet is by eating fatty fish two or three times a week. Salmon, sardines, herring, lake trout, and Atlantic mackerel all deliver meaningful amounts of DHA while staying low in mercury. If you don’t eat fish, algae-based supplements provide DHA that’s absorbed just as well as fish oil, and DHA-enriched eggs offer another option worth considering.
Why DHA Matters
DHA is a structural building block of your brain. It concentrates in the gray matter of your neurons, particularly at the junctions where brain cells communicate with each other. Once incorporated into cell membranes, DHA influences how flexible and permeable those membranes are, which directly affects how efficiently your neurons send and receive signals. It also promotes the growth of new neural connections and supports the activity of key signaling chemicals in the brain.
Beyond brain health, DHA plays a role in cardiovascular function. A meta-analysis published in The Journal of Nutrition found that supplementing with roughly 1.7 grams of algal DHA per day lowered blood triglycerides and raised HDL (the protective form of cholesterol) in people without existing heart disease. The American Heart Association recommends about 1 gram per day of combined EPA and DHA for people who already have coronary heart disease.
Best Fish Sources of DHA
Fatty, cold-water fish are the gold standard. A 3-ounce serving of cooked salmon delivers roughly 1,000 to 1,500 milligrams of combined EPA and DHA, depending on the species. Sardines, herring, Atlantic mackerel, and lake trout are all strong options that also stay on the low end for mercury contamination. Canned light tuna works too, though it provides less DHA per serving than fattier fish.
Fish to avoid or limit include shark, swordfish, king mackerel, marlin, orange roughy, and tilefish from the Gulf of Mexico, all of which tend to accumulate higher levels of mercury, dioxins, and PCBs. Eating whole fish appears to offer benefits beyond what supplements alone provide, likely because of the combination of protein, selenium, vitamin D, and other nutrients that come along with the omega-3s.
Plant-Based ALA Is Not a Substitute
Walnuts, flaxseeds, chia seeds, and hemp seeds are often marketed as omega-3 sources, and they are, but they contain ALA, a shorter-chain omega-3 your body must convert into DHA before it can use it the same way. That conversion is remarkably inefficient. Research published in Circulation reports that men convert roughly 0.05% of ALA into DHA. Women do better at around 10%, likely due to the influence of estrogen, but that still means the vast majority of ALA you eat never becomes DHA.
This doesn’t make ALA worthless. It has its own health benefits and contributes to overall omega-3 intake. But if your goal is specifically to raise DHA levels, relying on flax and walnuts alone won’t get you there.
Algae Oil for Vegetarians and Vegans
Algae is where fish get their DHA in the first place, so going straight to the source makes biological sense. Algal oil supplements derived from microalgae (typically a species called Schizochytrium) contain both DHA and EPA. In clinical testing, a standard dose of four algal oil capsules delivered about 1,772 mg of DHA and 656 mg of EPA per day.
The key question for anyone considering algae oil is whether it’s absorbed as well as fish oil. A head-to-head bioavailability study found that plasma levels of both DHA and EPA were statistically equivalent between the two sources. The researchers confirmed that algal oil is “nutritionally non-inferior” to fish oil, meaning your body uses it just as effectively despite the different composition and manufacturing process. For anyone avoiding animal products entirely, algal oil is the most practical way to get preformed DHA.
DHA-Enriched Eggs and Fortified Foods
DHA-enriched eggs come from hens fed diets containing flaxseed or marine byproducts, which raises the DHA content of the yolk. A single enriched egg typically provides 100 to 150 milligrams of DHA, compared to the negligible amount in a conventional egg. They’re widely available in most grocery stores.
How you cook those eggs actually matters for absorption. A study comparing different egg preparations found that an omelet delivered 56% more DHA into the bloodstream than a hard-boiled egg, and 120% more than a mousse made from the same enriched eggs. The reason comes down to digestion speed: softer, more fragile preparations move through the stomach and small intestine too quickly for full absorption, while the denser structure of a cooked omelet keeps the fats in contact with digestive enzymes longer.
Other fortified products on the market include certain brands of milk, yogurt, juice, and cereal bars. The bioavailability of DHA in these products varies considerably depending on the food matrix. A yogurt drink and a fitness bar, for instance, don’t necessarily deliver the same amount of usable DHA even if the label lists the same milligrams. Fortified foods can contribute to your intake, but they’re better thought of as a supplement to fish or algae oil rather than a primary source.
How to Maximize Absorption
DHA is a fat, and it absorbs best when eaten alongside other fats. Taking an omega-3 supplement on an empty stomach significantly reduces how much your body actually takes up. Research shows that consuming omega-3s as part of a fat-containing meal substantially increases absorption, because dietary fat triggers the digestive processes (bile release, enzyme activity) that break down and transport fatty acids into your bloodstream.
In practical terms, this means taking your DHA supplement with your largest meal of the day, or whichever meal contains the most fat. If you’re getting DHA from fish, this is a non-issue since the fish itself provides plenty of accompanying fat. For supplements, pairing them with avocado, nuts, olive oil, or even just a meal cooked with butter or oil makes a noticeable difference.
DHA During Pregnancy
DHA is critical during pregnancy because it accumulates rapidly in fetal brain and eye tissue, particularly during the third trimester. The European Food Safety Authority recommends that pregnant women consume an additional 100 to 200 mg of DHA per day on top of the 250 mg of combined DHA and EPA recommended for all adults.
Higher doses may be beneficial for some women. A large randomized trial published in eClinicalMedicine found that 1,000 mg of DHA daily reduced the odds of early preterm birth (before 34 weeks) in women who started pregnancy with low DHA levels. This doesn’t mean every pregnant woman needs a gram of DHA per day, but it does suggest that women with low fish intake or low baseline DHA status may benefit from more aggressive supplementation. Two to three servings of low-mercury fatty fish per week, potentially combined with an algal or fish oil supplement, is a reasonable approach during pregnancy and breastfeeding.
How Much DHA You Actually Need
There’s no single official recommended daily intake for DHA specifically. The U.S. Institute of Medicine has not set a standalone DHA recommendation, and guidelines vary by organization and health condition. For general health, most expert bodies suggest at least 250 mg of combined EPA and DHA per day, which you can meet with two servings of fatty fish per week.
People managing heart disease are generally advised to aim for about 1 gram of EPA plus DHA daily. For lowering elevated triglycerides, the threshold is considerably higher at around 4 grams per day, though doses that high are typically handled through prescription-strength formulations rather than over-the-counter supplements. If your diet includes little to no seafood, even a modest daily supplement of 200 to 500 mg of DHA can meaningfully shift your levels over a few weeks.