Selenium

Selenium is an essential trace mineral. Good food sources of selenium include: Brazil nuts, shrimp, crab, beef, chicken, brown rice, and whole wheat bread.1 The 100% Daily Value for Selenium (based on a 2000 kcal diet) is 70 mcg,2 but it has been revised to 55 mcg as of May 27, 2016.10 The 100% Daily Value for pregnant or lactating women is 70 mcg, effective as of January 1st, 2020.10

Forms

  • Selenium Yeast: Selenium yeast is a natural source of organically bound selenium. It is prepared by growing nutritional yeast cells (Saccharomyces cerevisiae) in a selenium-rich medium. Selenium is incorporated into the protein structure of the yeast cells that are then harvested and dried.

Major Health Benefits

Selenium is a trace mineral that functions as a component of antioxidant enzymes, including glutathione peroxidase. These selenium-dependent enzymes protect cellular components from oxidative damage by helping to neutralize free radicals. Selenium is also important for normal reproduction, immune system, and thyroid function.3 Selenium contributes to the maintenance of normal hair and nails.4 Although it is not conclusive, it has been suggested that low selenium levels may increase risk for prostate cancer.5-7

Cautions

The Tolerable Upper Intake Level (UL) of Selenium per day is 400 mcg.8 Excessive intake of Selenium can cause nail and hair brittleness, skin rashes, gastrointestinal disturbances, and fatigue.9

References

  1. Higdon, J. Selenium. Linus Pauling Institute, Oregon State University. 2001. (Reviewed by Whanger, PD in 2007) (Food Sources). http://lpi.oregonstate.edu/mic/minerals/selenium Accessed 7/2015.
  2. US Food and Drug Administration. Guidance for Industry: A Food Labeling Guide (14. Appendix F: Calculate the Percent Daily Value for the Appropriate Nutrients). US Department of Health and Human Services. 2013 January. https://www.fda.gov/downloads/Food/GuidanceRegulation/GuidanceDocumentsRegulatoryInformation/UCM265446.pdf
  3. European Food Safety Authority. Scientific Opinion on Selenium Health Benefits. EFSA Journal 2009; 7(9): 1220. https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2009.1220
  4. European Food Safety Authority. Scientific Opinion on Selenium Health Benefits. EFSA Journal 2010; 8(10): 1727. https://efsa.onlinelibrary.wiley.com/doi/epdf/10.2903/j.efsa.2010.1727
  5. Brinkman M, Reulen RC, Kellen E, Buntinx F, Zeegers MP. Are men with low selenium levels at increased risk of prostate cancer? Eur J Cancer. 2006 Oct;42(15):2463-71. PMID: 16945521.
  6. Brooks JD, Metter EJ, Chan DW, et al. Plasma selenium level before diagnosis and the risk of prostate cancer development. J Urol. 2001 Dec;166(6):2034-8. PMID: 11696701.
  7. Yoshizawa K, Willett WC, Morris SJ, et al. Study of prediagnostic selenium level in toenails and the risk of advanced prostate cancer. J Natl Cancer Inst. 1998 Aug 19;90(16):1219-24. PMID: 9719083.
  8. Dietary Reference Intakes (DRIs): Tolerable Upper Intake Levels, Elements. Food and Nutrition Board, Institute of Medicine, The National Academic Press. 2001. (PDF available)
  9. Higdon, J. Selenium. Linus Pauling Institute, Oregon State University. 2001. (Reviewed by Whanger, PD in 2007) (Safety) https://lpi.oregonstate.edu/mic/minerals/selenium#safety
  10. US Food and Drug Administration. Food Labeling: Revision of the Nutrition and Supplement Facts Labels. US Department of Health and Human Services. Federal Register / Vol. 81, No. 103, p. 33982 / May 27, 2016. https://www.gpo.gov/fdsys/pkg/FR-2016-05-27/pdf/2016-11867.pdf