Selenium

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 Question mark: This treatment has not been properly researched. It is not possible to say whether they are useful or not.

What is it?

Selenium is an essential trace element found in many foods.

How does it work?

Low levels of selenium in the diet may have an effect on mood. Some countries have a low level of selenium in the soil. This in turn affects the amount of selenium available in food. It has been proposed that people living in these countries may need selenium supplements. The countries affected include New Zealand, United Kingdom and parts of China, Scandinavia and the United States. Australian soil is not deficient in selenium and the average Australian diet contains adequate selenium.

Is it effective?

There have been some studies which have looked at the impact of selenium supplements on mood in the general population. The results of these studies have been mixed – some studies found that people who took selenium supplements had small improvements in their mood, while others have found that selenium had no impact on mood.

Selenium has not been tested specifically with people who have clinical depression.

Are there any disadvantages?

Selenium can be toxic in high doses. If you would like to take selenium supplements, ask your doctor or pharmacist what dose is right for you, and ask it if might interfere with other medications or supplements you are taking.

Where do you get it?

Selenium supplements are available from health food shops. Foods rich in selenium include brazil nuts, seafood, meats and fortified cereals.

Recommendation

Selenium supplements may be helpful for people with a selenium deficiency. But, given the lack of evidence on selenium, it cannot be recommended as a treatment for depression.  

Key references

  • Benton D, Cook R. The impact of selenium supplementation on mood. Biological Psychiatry 1991; 29: 1092-1098.
  • Rayman M, Thompson A, Warren-Perry M, Galassini R, Catterick J, Hall E, et al. Impact of selenium on mood and quality of life: a randomized, controlled trial. Biol Psychiatry. 2006 Jan 15; 59(2): 147-54.
  • Wang J, Um P, Dickerman BA, Liu J. Zinc, magnesium, selenium and depression: A review of the evidence, potential mechanisms and implications. Nutrients. 2018; 10(5): 584.

Last reviewed and updated: 1 November 2019