Selenium Supplementation for Vegetarians and Vegans

Vegetarians and vegans, do they get enough selenium in their diets? It is an important question because the number of vegetarians around the world is growing for ethical and environmental reasons. How do we measure selenium status in various groups of people?

Vineyard in Germany with selenium-poor soil
The arable land in much of Europe contains a sub-optimal content of selenium, meaning that the plants grown there are also poor in selenium. Pictured: A vineyard in Germany.

Selenium is an essential trace element. Essential means that we have to get it from our food or from supplements. The human body does not synthesize selenium. What the body does synthesize is the selenoproteins, of which selenium in the amino acid selenocysteine is a key active component.

Particularly in much of Europe and the Middle East, the soil and the plants have relatively poor selenium content. In many countries, the farm animals are supplemented with selenium to improve their nutritional intakes and their health and to avoid selenium deficiency syndromes.

Do German Vegetarians have selenium deficiency?

In Germany, researchers investigated whether vegetarians present with a measurable selenium deficiency [Hoeflich 2010].

First, they compared young vegetarians (n = 54) and omnivores (n = 53). They measured their selenium status by doing three different assessments:

  • extracellular glutathione peroxidase 3 (GPX3) activity
  • total serum selenium concentration
  • circulating selenium-transport protein selenoprotein P levels
German Vegetarians’ Selenium Status

The vegetarian study yielded the following results. The researchers saw that relying on a single measure of selenium status could give a misleading picture of an individual’s selenium status. [Hoeflich 2010]:

  • The level of GPX3 activity was not different between the two groups.
  • The concentrations of both total serum selenium and serum selenoprotein P were significantly lower in the vegetarian group: 79.5% and 71.2% in the vegetarians compared with the omnivores.
Selenium Status of Vegans Compared to Vegetarians

When the German researchers split the group of vegetarians into vegans (n = 26) and vegetarians who did consume milk and egg products (n = 28), they found that none of the three selenium-dependent biomarkers showed a significant difference between the two groups [Hoeflich 2010].

Conclusion: Selenium intakes of Vegetarians and vegans

Studies comparing selenium concentrations in vegetarians and omnivores from different countries worldwide have not yielded consistent results. However, serum selenium concentrations in vegans and vegetarians have tended to be lower, especially in regions with marginal selenium intakes [Hoeflich 2010].

The German researchers concluded that low serum selenium status is reflected by low circulating selenoprotein P concentrations but not by reduced GPX3 activity in individuals who are marginally supplied with selenium in their diets [Hoeflich 2010].

Accordingly, depending on the choice of biomarker, individuals could be classified as selenium deficient or selenium sufficient [Hoeflich 2010].

The use of a combination of biomarkers of selenium status – total selenium status, selenoprotein P status, and GPX3 activity – may give a clearer picture of the selenium status of any one individual [Hoeflich 2010].

Note that selenoprotein P status is a useful biomarker of an individual’s selenium status because the biosynthesis of the selenoprotein P in the liver plateaus when a replete selenium status has been achieved [Schomburg & Melander 2019].

Plasma glutathione peroxidase seems to reach a plateau at a plasma/serum selenium concentration of 70 mcg/L. By contrast, in a selenium-replete US cohort with an average plasma selenium concentration of 125 mcg/L, no further increase of selenoprotein P was detected after selenium supplementation with 200 or 600 mcg/day, suggesting that this is the level at which the synthesis of selenoprotein P plateaus [Hurst 2010].


Hoeflich J, Hollenbach B, Behrends T, Hoeg A, Stosnach H, Schomburg L. The choice of biomarkers determines the selenium status in young German vegans and vegetarians. Br J Nutr. 2010 Dec;104(11):1601-4.

Hurst R, Armah CN, Dainty JR, Hart DJ, Teucher B, Goldson AJ, Broadley MR, Motley AK, Fairweather-Tait SJ. Establishing optimal selenium status: results of a randomized, double-blind, placebo-controlled trial. Am J Clin Nutr. 2010 Apr;91(4):923-31.

Schomburg L & Melander O. Letter by Schomburg and Melander Regarding Article, “Selenoprotein P Promotes the Development of Pulmonary Arterial Hypertension: A Possible Novel Therapeutic Target”. Circulation. 2019;139(5):722-23.

The information presented in this review article is not intended as medical advice and should not be used as such.

15 April 2023


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