Clinical Trial of DHA Supplementation in Vegans


A 172 mg DHA / 82 mg EPA supplement for 2 months increased levels in vegans to those typical of fish-eaters.

A recently released study measured the omega-3 status of vegans and then placed those with low omega-3 status on an EPA/DHA supplement for two months (1).

The cross-sectional part of the study found that 166 vegans had an average EPA level of .63% (of total fatty acids in red blood cells) and an average DHA level of 2.4%. In comparison to other studies that have measured the percentage of EPA/DHA in meat-eaters in similar ways, those numbers are on the low side, especially for EPA.

The researchers compared a group of the male vegans to a group of male soldiers deployed to Iraq who had very low fish intakes and the vegans had significantly higher levels of EPA and slightly lower levels of DHA.

The researchers then took a group of vegans with low omega-3 levels and gave them a supplement of 172 mg DHA and 82 mg EPA for 2 months. EPA went from about .6% to .8% and DHA increased from about 2.3% to 3.25%.

In other words, this supplementation schedule was adequate for raising EPA/DHA levels to those typical of fish-eaters.

I have updated Omega-3 Fatty Acid Recommendations for Vegetarians with this information.


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1. Sarter B, Kelsey KS, Schwartz TA, Harris WS. Blood docosahexaenoic acid and eicosapentaenoic acid in vegans: Associations with age and gender and effects of an algal-derived omega-3 fatty acid supplement. Clin Nutr. 2014 Mar 14. pii: S0261-5614(14)00076-4. doi: 10.1016/j.clnu.2014.03.003. [Epub ahead of print] | link

8 Responses to “Clinical Trial of DHA Supplementation in Vegans”

  1. Dan Says:

    This is a great paper – it’s always great to see clinical trials done in this population – but the same question remains: do we truly need DHA or is DHA just acting as a marker of something else?

    One thing that’s really good about this paper is that it shows that non-vegans who don’t eat fish end up with the same low EPA/DHA status as true vegans (who of course don’t eat fish). Since most of the recent large, neutral, clinical trials (there have now been six of them – AREDS2, SU.FOL.OM3, OMEGA, Alpha Omega, ORIGIN, and R & P) would have enrolled predominantly non-vegans (who make up 98-99% of the general population), and most of them did stratified analyses by fish intake and/or DHA levels, yet showed no benefit in any of the low groups, I am beginning to believe that these trials (and their neutral results) could actually extrapolate to vegans, at least for cardiovascular health. Neurologic health is an entirely different story and a ‘black box’.

  2. Brandon Becker Says:

    I get bruises when I take supplemental DHA and especially DHA+EPA (even at doses as low as in this study). Does this mean that without supplements, my body is already producing enough DHA and EPA from ALA? In my diet calculations on, I always end up over the RDA for ALA.

  3. Jack Norris RD Says:

    > Does this mean that without supplements, my body is already producing enough DHA and EPA from ALA?

    It might. Bruising is more a function of EPA than DHA, though.

  4. Charlotte Says:

    I take an algae-based omega 3 DHA/EPA supplement quite regularly, following your recommendations. However, I read elsewhere on that algae may interfere with B12 metabolism – is this a concern with the supplements?
    Thank you for all your amazing work on vegan nutrition!

  5. Jack Norris RD Says:

    Charlotte– No, the omega-3s are separated from the algae and there should be no B12 analogues in the supplement.

  6. Ari Says:

    Hi Dr. Jack Norris

    in my country (brazil), there is only a DHA supplement, with no EPA. is it enough? the body normally produces enough EPA? and also it’s quite expensive, so taking like 1 or 2 200mg DHA tablet a week should be ok for increasing the DHA levels?

  7. Jack Norris RD Says:


    DHA of 200 mg 1-2 times a week should increase your levels somewhat. But you should also include some short chain omega-3s as suggested here:

    Yes, there are tests for blood levels of DHA, but I don’t know if you’d have access in Brazil. I’d start looking at Google. If you’re a young, apparently healthy vegan I probably wouldn’t worry about getting tested. I’ve never had mine tested.

  8. Ari Says:

    also, is there a blood test available for measuring DHA/EPA levels in blood?

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