selenium
What is selenium?
Selenium is an essential trace mineral, meaning that the body only requires a small amount to maintain healthy levels. As an essential mineral, it is vital to the human body and needs to be consumed regularly.[1] Selenium is absorbed in the intestinal tract and stored mostly in the skeletal muscle.[2]
Why is selenium so important?
As an antioxidant, selenium helps to protect the body’s cells and tissues from free radical damage. Low antioxidant intake, including low selenium, can lead to an excessive type of free radical damage called oxidative stress. This is a process in the body in which healthy cells become damaged and unstable, potentially causing poor health outcomes.[3]
Selenium is essential to maintaining the healthy function of the thyroid gland. The thyroid gland requires higher concentrations of selenium and is needed for the production and metabolism of thyroid hormones. As an antioxidant, selenium helps protect the thyroid from oxidative damage.[4]
The source
Eimele’s source of selenium is in the form of selenomethionine - an organic selenium that is well absorbed and utilised by the human body.[5]
Optimal dosage
RDI6
- Men 19-70+ years 70micrograms/day
- Women 19-70+ years 60micrograms/day
- Pregnancy 65micrograms/day
- Lactation 75micrograms/day
- The upper level of intake for all adults is 400micrograms/day.[6]
Why do we need to supplement selenium?
Around 1 billion people globally are thought to be selenium deficient. Selenium can only be found in foods that have been grown in selenium-rich soil - selenium soil content can vary from region to region, but many countries lack adequate selenium levels in the soil.[7]
This can leave many people selenium deficient and in need of supplementation.
Interesting facts about selenium
- The thyroid gland has the highest amount of selenium per gram of tissue compared to all the other organs of the human body.[4]
- Selenium tends to be highest in volcanic soils.[8]
References:
[1]. Harvard. Selenium. Accessed July 2022 from https://www.hsph.harvard.edu/nutritionsource/selenium/#:~:text=It%20is%20found%20naturally%20in,the%20metabolism%20of%20thyroid%20hormones.
[2]. Fairweather-Tait, S.J., Collings, R. & Hurst, R. (2010). Selenium bioavailability: current knowledge and future research requirements. The American Journal of Clinical Nutrition, 91(5):1484S-1491S.
[3]. Zakeri, N., Rezaei Kelishadi, R., Asbaghi, O., Naeini, F., Afsharfar, M., et al. (2021). Selenium supplementation and oxidative stress: a review. PharmaNutrition, 1:100263.
[4]. Ventura, M., Melo, M. & Carrilho, F. (2017). Selenium and thyroid disease: from pathophysiology to treatment. Int J Endocrinol, 2017:1297658.
[5]. National Institutes of Health. Selenium. Updated March 2021, accessed July 2022 from https://ods.od.nih.gov/factsheets/Selenium-HealthProfessional/.
[6]. National Health and Medical Research Council. Selenium. Updated April 2014, accessed July 2022 from https://www.nrv.gov.au/nutrients/selenium
[7]. Lopes, G. Avila, F.W. & Guimaraes Guilherme, L.R. (2017). Selenium behaviour in the soil environment and its implications for human health. Science Agrotech, 41(6).
[8]. Dagnew Gebreeyessus, G. & Zewge, F. (2018). A review on environmental selenium issues. SN Applied Sciences, 1(55).