How Do You Get Enough Omega-3 on a Vegan Diet? ALA, Algal EPA and DHA

A vegan diet supplies the essential omega-3, ALA, easily: two tablespoons of ground flaxseed, 25 g of chia, 30 g of walnuts or a tablespoon of flaxseed oil each reaches the 2 g a day at which the register's ALA wording applies. What it does not supply is EPA and DHA, because most adults convert only about 5% of ALA to EPA and almost none to DHA. The direct route is algal oil, the same DHA molecule the fish got from algae: 600 mg of algal DHA a day raised blood DHA as much as the same amount from cooked salmon.^{1, 2}

• ALA: flaxseed, chia, walnuts, hemp, rapeseed oil and soya; 2 g a day from one or two servings
• EPA and DHA: about 5% and under 1% of ALA becomes them; algal oil supplies them ready-made
• The yardstick: 250 mg EPA+DHA (heart), 250 mg DHA (brain, vision), 200 mg more DHA in pregnancy

Sources checked on 29 October 2026.

How do vegans get omega-3?

Alpha-linolenic acid (ALA) is the plant omega-3 and the only one the body strictly cannot make; the NHS lists ground linseed (flaxseed), rapeseed oil, chia seeds, shelled hemp seeds and walnuts as vegan sources.³ EPA and DHA are made by marine algae and concentrated into oily fish; algal oil takes them straight from the algae. The Wellgard omega-3 guide explains what each fat does. The protein side of a vegan plate is on vegan protein sources.

How much flaxseed, chia or walnut gives the ALA I need?

The register's wording, that ALA contributes to the maintenance of normal blood cholesterol levels, applies at 2 g a day.⁴ Approximate ALA per portion:⁵

Does flaxseed oil contain omega-3, 6 and 9 covers the oil; what foods are high in omega-3, 6 and 9 has more.

Does ALA convert to EPA and DHA?

A little to EPA, almost none to DHA, and women convert more than men. In tracer studies, young women turned about a fifth of a labelled ALA dose into EPA and 9% into DHA, while men made EPA and very little or no DHA; the reading across studies is about 5% to EPA and under 1% to DHA.^{2, 6, 18} In a 12-week trial, 2.4 to 3.6 g of flaxseed oil a day raised red-cell EPA; DHA did not rise.^{6, 7} The linoleic acid that vegan diets are rich in competes for the same enzymes and lowers conversion further.⁵ So ALA is not useless, and flaxseed is not "as good as fish oil" for DHA.

Why do vegans have a lower omega-3 index, and does it matter?

The omega-3 index is EPA plus DHA as a percentage of red-cell fatty acids; its authors proposed 8% or more as the lowest-risk band for coronary death and 4% or less as the highest.⁸ In 165 long-term vegans the mean was 3.7%, the same as omnivores who ate little fish.⁹ In 14,422 people in Norfolk, non-fish-eaters' blood levels sat much closer to fish-eaters' than their intakes predicted, with higher estimated conversion in women and non-fish-eaters.¹⁰ A low index is a reason to add DHA, not an emergency.

Do vegan omega-3 supplements work?

Algal ones do. In the equivalence trial, algal DHA matched cooked salmon on blood DHA over two weeks.¹ A systematic review found algal DHA raised blood DHA and the omega-3 index in vegetarians and vegans in all six of its studies.¹² In 46 of those vegans with an index below 4%, 254 mg of algal EPA and DHA a day for four months lifted it from 3.1% to 4.8%.⁹ A flaxseed-based "vegan omega-3" supplies ALA, not DHA.

How much algal DHA should a vegan take?

Use the register's thresholds in the box above as the yardstick.⁴ SACN's UK figure is 450 mg a day, what two portions of fish a week supply, and EFSA found no safety concern at up to 5 g a day.^{13, 14} In the large trials the risk of new atrial fibrillation rose about 50% above 1 g a day and about 12% at 1 g or less, so keep to label doses; why is fish oil no longer recommended sets that out.¹⁵ Read milligrams of DHA per serving, not milligrams of oil: a "500 mg algal oil" capsule may carry 100 to 250 mg of DHA, and some algal oils add EPA; how much omega 3-6-9 do I need daily has worked examples.

What is the best vegan omega-3?

The one whose label answers five questions: milligrams of DHA per daily serving, against 250 mg; whether EPA is included; the capsule shell, since some vegan oils come in gelatine; freshness, since a strong fishy or paint-like taste is oxidation; and vitamin A, if you are pregnant or buying for a child.

What is vegan omega 3-6-9?

Flaxseed oil in a capsule: a plant ALA supplement. A two-capsule serving typically supplies several hundred milligrams of ALA, against the 2 g a day at which the register's ALA cholesterol wording applies, with smaller amounts of linoleic and oleic acid and often vitamin E, which contributes to the protection of cells from oxidative stress; it contains no EPA or DHA, so it sits alongside an algal source. For the DHA itself, a vegan omega-3 gummy typically supplies tens of milligrams of algal DHA per two-gummy serving, against the 250 mg behind the register's brain and vision wording, often with vitamin D, which contributes to the maintenance of normal bones and teeth, and vitamins A and C, which contribute to the normal function of the immune system; keep to the label serving, especially for children. Is it better to take omega-3 or omega 3-6-9 compares them.

Vegan omega-3 in pregnancy and childhood

The register's maternal wording, "Docosahexaenoic acid (DHA) maternal intake contributes to the normal brain development of the foetus and breastfed infants", with a twin for the normal development of the eye, applies at 200 mg of DHA a day on top of the adult 250 mg.⁴ In the Cochrane review of 70 trials, omega-3 in pregnancy reduced early preterm birth from 4.6% to 2.7%; an analysis of one trial found the benefit in women with low blood omega-3, and more early preterm births when women already high in omega-3 were supplemented.^{16, 17} The NHS says long-chain omega-3 helps the baby's nervous system develop and to avoid fish liver oil supplements when pregnant or trying, because of their vitamin A; a plain algal DHA oil meets both.¹¹ For children, the NHS notes that under-twos have different needs and points to specialist guidance for under-fives; use ALA foods daily and, for DHA, an algal product labelled for the child's age.³

What we don't know

No trial has tested algal DHA against a health outcome in vegans; the evidence is blood levels.¹² How much ALA a given vegan converts is unknown: tracer studies range from almost none in men to about a fifth in young women.⁶ Whether vegans' lower omega-3 index carries any risk is unshown either way.⁸

Frequently asked questions

How can I increase my omega-3 without eating fish?

Add 2 g of ALA a day from the table above, and DHA from algal oil.^{1, 7}

Are there any vegan omega-3 supplements available?

Two kinds: algal oils and gummies supplying DHA (sometimes EPA), and flaxseed oils and 3-6-9 capsules supplying ALA.

What is vegan omega-3 good for?

The register answers by amount: 250 mg of EPA and DHA for normal heart function, 250 mg of DHA for normal brain function and vision, 2 g of ALA for normal blood cholesterol.⁴

Can I take vegan omega-3 every day?

Yes, with a meal; the trials dosed daily, and EFSA found no safety concern up to 5 g of EPA and DHA a day.¹⁴

Sources

1. Arterburn LM, et al. Algal-oil capsules and cooked salmon: nutritionally equivalent sources of DHA. Journal of the American Dietetic Association, 2008. Randomised open-label trial, 32 adults, 2 weeks; lead author at a pharmaceutical company. PubMed 18589030.
2. Plourde M, Cunnane SC. Extremely limited synthesis of long chain polyunsaturates in adults. Applied Physiology, Nutrition, and Metabolism, 2007. Review; funding not stated on PubMed. PubMed 17622276.
3. NHS. The vegan diet. nhs.uk. Page last reviewed 5 June 2026.
4. Great Britain nutrition and health claims (NHC) register. gov.uk. Last updated 19 May 2026.
5. Burns-Whitmore B, et al. Alpha-linolenic and linoleic fatty acids in the vegan diet. Nutrients, 2019. Review with a USDA food table; no conflicts declared. PubMed 31590264.
6. Burdge GC, Calder PC. Conversion of alpha-linolenic acid to longer-chain polyunsaturates in adults. Reproduction Nutrition Development, 2005. Review; funding not stated on PubMed. PubMed 16188209.
7. Barceló-Coblijn G, et al. Flaxseed oil and fish-oil capsules alter red blood cell n-3 fatty acids. American Journal of Clinical Nutrition, 2008. Randomised trial, 62 firefighters, 12 weeks; publicly funded (NIH). PubMed 18779299.
8. Harris WS, von Schacky C. The Omega-3 Index: a new risk factor for death from coronary heart disease? Preventive Medicine, 2004. Risk-factor proposal from trial data; funding not stated on PubMed. PubMed 15208005.
9. Sarter B, et al. Blood DHA and EPA in vegans and effects of an algal-derived omega-3 supplement. Clinical Nutrition, 2015. Survey of 165 vegans with a 46-person, 4-month supplement arm; funding not stated on PubMed. PubMed 24679552.
10. Welch AA, et al. n-3 fatty acid intake and status in fish-eaters and non-fish-eaters (EPIC-Norfolk). American Journal of Clinical Nutrition, 2010. Cohort study, 14,422 adults; funding not stated on PubMed. PubMed 20861171.
11. NHS. Fish and shellfish. nhs.uk. Page last reviewed 26 June 2026.
12. Craddock JC, et al. Algal supplementation of vegetarian eating patterns improves DHA. Journal of Human Nutrition and Dietetics, 2017. Systematic review, 4 trials and 2 cohorts; funding not stated on PubMed. PubMed 28417511.
13. SACN. Advice on fish consumption: benefits and risks. gov.uk. Published 1 December 2004.
14. EFSA. EFSA assesses safety of long-chain omega-3 fatty acids. efsa.europa.eu. Published 27 July 2012.
15. Gencer B, et al. Marine omega-3 supplementation and the risk of atrial fibrillation. Circulation, 2021. Meta-analysis, 7 trials, 81,210 people; publicly funded (NIH). PubMed 34612056.
16. Middleton P, et al. Omega-3 fatty acid addition during pregnancy. Cochrane Database of Systematic Reviews, 2018. Cochrane review, 70 trials, 19,927 women; non-commercial funding. PubMed 30480773.
17. Simmonds LA, et al. Omega-3 supplementation in pregnancy: baseline status and early preterm birth. BJOG, 2020. Exploratory analysis of one randomised trial; funding not stated on PubMed. PubMed 32034969.
18. Burdge GC, Wootton SA. Conversion of alpha-linolenic acid to EPA, DPA and DHA in young women. British Journal of Nutrition, 2002. Tracer study, young women, 21 days; funding not stated on PubMed. PubMed 12323090.

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This article is general information, not medical advice. If you are pregnant, breastfeeding, choosing a supplement for a child or take an anticoagulant, speak to your GP, midwife or pharmacist before adding an omega-3 supplement.