Last updated January 2019
- Dietary Reference Intakes for Selenium
- Selenium Content of Plant Foods
- Selenium Intakes and Status of Vegans
Selenium is an essential mineral that is needed in very small (trace) amounts. Selenium is involved in protection from oxidative damage, reproduction, DNA synthesis, and thyroid hormone metabolism. The selenium content of plant foods depends on the selenium content of the soil where the foods were grown (1).
Vegans in the U.S. appear to have adequate intakes of selenium (2). Low intakes and lower blood concentrations have been reported in vegans and vegetarians in other areas of the world where soil selenium is low (2, 3, 4, 5).
Dietary Reference Intakes for Selenium
The Recommended Dietary Allowance (RDA) for selenium is 55 micrograms per day for adolescents and adults, 60 micrograms per day during pregnancy, and 70 micrograms per day when breastfeeding (6). Most Americans get more than the RDA and over 99% of participants in a large survey of people in the U.S. had serum selenium in the normal range (6).
Selenium Content of Plant Foods
The selenium content of plant foods depends on the amount of selenium in the soil the plants were grown in as well as on other factors including soil pH and fertilizer use (1). The amount of selenium in soil varies by geographic location.
The lowest selenium intakes in the world are in some parts of China where soil selenium is very low (2), while other regions of China have a very high soil selenium and high selenium intakes (1). Areas of Europe also have low soil selenium (1) although not as low as in China. New Zealand soil is low in selenium but selenium intakes are adequate because of the use of imported high-selenium wheat (2).
In the U.S and Canada, selenium intakes, even in areas with lower soil selenium, are generally adequate (7, 8, 9). This is, at least in part, due to the food distribution system which usually makes it possible for even those living in areas with lower soil selenium to get enough selenium.
Selenium values in food composition tables may or may not reflect the actual selenium content of foods eaten by an individual. For example, the USDA Food Composition Database reports that Brazil nuts have 544 micrograms of selenium per ounce but other sources report values ranging from 45 to 566 micrograms/ounce (10, 11, 12).
In addition to Brazil nuts, foods that are relatively high in selenium include whole grains (whole-wheat bread and pasta, oatmeal, barley), brown rice, soy products, and beans. The table below shows the selenium content of selected plant foods from the USDA’s nutrient database (12). Note that selenium content will vary depending on soil selenium.
|Selenium in Plant Foods in the United States|
|Food||Serving Size|| Selenium
|Brazil nuts||1 ounce (about 6 nuts)||544|
|Couscous, cooked||1 cup||43|
|Whole-wheat pasta, cooked||1 cup||42|
|Sunflower seed butter||2 tablespoons||33|
|Wheat bagel||1 bagel||28|
|Sunflower seeds, dry roasted||1 ounce||23|
|Wheat germ, toasted||1 ounce||18|
|Chia seeds||1 ounce||16|
|Whole-wheat tortilla||1 tortilla||15|
|Barley, pearled, cooked||1 cup||13.5|
|Soybeans, cooked||1 cup||13|
|Oatmeal, cooked||1 cup||13|
|Firm tofu||½ cup||12.5|
|Brown rice, cooked||1 cup||12|
|Pinto beans, cooked||1 cup||11|
|Lima beans, cooked||1 cup||8.5|
|Whole-wheat bread||1 slice||8|
|Great northern beans||1 cup||7|
Selenium Intakes and Status of Vegans
Vegans in the U.S. appear to have adequate intakes of selenium (2).
Depending on food choices, vegans in Europe may have lower intakes of selenium. Lower soil selenium in European countries affects the selenium content of locally-grown grains, fruits, and vegetables.
In Denmark, both vegans and the general population had median selenium intakes that were lower than recommendations; the vegans had significantly lower selenium intakes than the general population (4).
One brief report from 1997 found lower selenium status in UK vegans than in UK non-vegetarians (3).
A more recent study in the U.K. found lower mean selenium intakes in lacto-ovo and lacto vegetarians compared to meat or fish eaters. Vegans’ mean selenium intakes were lower than those of meat/fish eaters but higher than lacto-ovo/lacto vegetarians (13).
Almost half of vegan women and one-third of vegan men in the U.K. had selenium intakes below recommendations (13).
In Finland, vegans had lower selenium intakes and lower blood selenium compared to non-vegetarians (14). Both groups, however, had selenium intakes that met or exceeded recommendations and serum selenium was in an acceptable range (14). Finland is unique in that it adds selenium to fertilizers (15).
As of January 2019, information on selenium intakes and status of vegans in other areas of the world was not found.
Vegans in the U.S. and other areas eating a variety of foods including whole grains and beans are likely to get enough selenium. Vegans in low selenium areas should eat Brazil nuts regularly and/or to use a supplement supplying a moderate amount of selenium.
The tolerable upper intake level (UL) for selenium is 400 μg/day for adolescents and adults and includes both selenium obtained from food and selenium from supplements (6). Long-term use of high amounts of selenium can cause health problems including hair and nail loss or brittleness, nausea, diarrhea, fatigue, and neurologic disorders (16).
5. Sobiecki JG. Vegetarianism and colorectal cancer risk in a low-selenium environment: effect modification by selenium status? A possible factor contributing to the null results in British vegetarians. Eur J Nutr. 2017 Aug;56(5):1819-1832.
8. Kafai MR, Ganji V. Sex, age, geographical location, smoking, and alcohol consumption influence serum selenium concentrations in the USA: third National Health and Nutrition Examination Survey, 1988-1994. J Trace Elem Med Biol 2003;17:13-8.
13. Sobiecki JG, Appleby PN, Bradbury KE, Key TJ. High compliance with dietary recommendations in a cohort of meat eaters, fish eaters, vegetarians, and vegans: results from the European Prospective Investigation into Cancer and Nutrition-Oxford study. Nutr Res. 2016 May;36(5):464-77.
15. Alfthan G, Eurola M, Ekholm P, et al. Effects of nationwide addition of selenium to fertilizers on foods, and animal and human health in Finland: From deficiency to optimal selenium status of the population. J Trace Elem Med Biol. 2015;31:142-7.