Omega-3 (EPA + DHA)
EPA and DHA. The two fatty acids fish oil is actually valued for.
Omega-3 refers to EPA and DHA, two long-chain fatty acids linked to cardiovascular and brain health that the body makes only in small amounts from plant-based precursors. Triglyceride-form fish oil is absorbed roughly 50% better than the cheaper ethyl ester form and should be taken with a fat-containing meal; algae oil provides DHA at a level equivalent to fish sources and is the standard vegetarian and vegan option; krill oil's phospholipid structure shows comparable or modestly better absorption at the same dose. European guidance sets an adequate intake of 250mg a day combined EPA and DHA, roughly what two portions of oily fish a week provides, with a supplemental upper limit set considerably higher than that.
Reference values
Daily reference values from official nutrition authorities. These are population reference figures, not personal recommendations.
| RDA | Upper limit | Source |
|---|---|---|
| 250 mg | 5000 mg | EFSA NDA Panel AI 250mg/day combined EPA+DHA (2010 DRV opinion). UL 3000mg/day is FDA GRAS guidance (a source outside SACN/EFSA/NIH/WHO) — EFSA's 2012 opinion on EPA/DHA/DPA safety explicitly found insufficient data to set a formal UL. SACN has not set a formal RNI for EPA+DHA specifically. |
| 250 mg | 3000 mg | EFSA NDA Panel AI 250mg/day combined EPA+DHA (2010 DRV opinion). UL 3000mg/day is FDA GRAS guidance (a source outside SACN/EFSA/NIH/WHO) — EFSA's 2012 opinion on EPA/DHA/DPA safety explicitly found insufficient data to set a formal UL. SACN has not set a formal RNI for EPA+DHA specifically. |
Forms and bioavailability
Not all forms are absorbed equally. The form on your supplement label affects how much your body can actually use.
| Form | Absorption | With food | Timing | Evidence |
|---|---|---|---|---|
| Fish oil (triglyceride form) | Typical | With food | Either | Strong |
| Algae oil (DHA-dominant) | Typical | With food | Either | Strong |
| Krill oil (phospholipid form) | Higher | With food | Either | Possible |
| Fish oil (ethyl ester form) | Lower | With food | Either | Likely |
How it pairs with other supplements
Works well with
Omega-3 fatty acids and vitamin D share complementary anti-inflammatory pathways and are commonly co-supplemented for immune and cardiovascular health. Some evidence suggests omega-3 enhances vitamin D receptor signalling in immune cells.
Choline is the head-group precursor for phosphatidylcholine (PC), and omega-3 fatty acids (DHA in particular) are esterified into PC membrane phospholipids. Together they support neuronal and cell membrane phospholipid composition, relevant for cognitive and cardiovascular membrane function.
Stack Almanac tracks your omega-3 form and totals EPA plus DHA across every source, alongside vitamin D and choline if you're taking those too.
Track your Omega-3 (EPA + DHA) in Stack Almanac
Last reviewed: 2026-07-08. Reference values are adult-general RDAs from other. Individual needs may vary. This page is for informational purposes only and is not a substitute for professional medical advice.