Find Information About:

Drugs & Supplements

Get information and reviews on prescription drugs, over-the-counter medications, vitamins, and supplements. Search by name or medical condition.

Pill Identifier

Pill Identifier

Having trouble identifying your pills?

Enter the shape, color, or imprint of your prescription or OTC drug. Our pill identification tool will display pictures that you can compare to your pill.

Get Started

My Medicine

Save your medicine, check interactions, sign up for FDA alerts, create family profiles and more.

Get Started

WebMD Health Experts and Community

Talk to health experts and other people like you in WebMD's Communities. It's a safe forum where you can create or participate in support groups and discussions about health topics that interest you.

  • Second Opinion

    Second Opinion

    Read expert perspectives on popular health topics.

  • Community


    Connect with people like you, and get expert guidance on living a healthy life.

Got a health question? Get answers provided by leading organizations, doctors, and experts.

Get Answers

Sign up to receive WebMD's award-winning content delivered to your inbox.

Sign Up

Font Size

Prostate Cancer, Nutrition, and Dietary Supplements (PDQ®): Complementary and alternative medicine - Health Professional Information [NCI] - Selenium


This section contains the following key information:

Recommended Related to Prostate Cancer

Treatment for Prostate Cancer

There’s no one prostate cancer treatment that’s right for every man, but you've got plenty of options. Your doctor will consider many things when he recommends one for you, including: The size of your tumor and how far it has spread, called the stage of your disease How quickly the tumor is likely to grow Your age and how healthy you are Your personal preferences

Read the Treatment for Prostate Cancer article > >

  • Selenium is an essential trace mineral involved in a number of biological processes, including kinase regulation, gene expression, and immune function.
  • Animal and epidemiological studies have suggested there may be an inverse relationship between selenium supplementation and cancer risk.
  • The results of epidemiologic studies suggest some complexity in the association between blood levels of selenium and the risk of developing prostate cancer.
  • The Selenium and Vitamin E Cancer Prevention Trial (SELECT), a large multicenter clinical trial, was initiated to examine the effects of selenium and/or vitamin E on the development of prostate cancer.
  • Initial results of SELECT, published in 2009, showed no statistically significant difference in the rate of prostate cancer in men who were randomly assigned to receive the selenium supplements.
  • In 2011, updated results from SELECT showed no significant effects of selenium supplementation on risk, but men who took vitamin E alone had a 17% increase in prostate cancer risk compared with men who took placebo.
  • In 2014, an analysis of SELECT results showed that men who had high selenium status at baseline and who were randomly assigned to receive selenium supplementation had an increased risk of high-grade prostate cancer.

General Information and History

Selenium is an essential trace mineral involved in a number of biological processes, including enzyme regulation, gene expression, and immune function. Selenium was discovered in 1818 and named after the Greek goddess of the moon, Selene.[1] A number of selenoproteins have been identified in humans, including selenoprotein P (SEPP), which is the main selenium carrier in the body and is important for selenium homeostasis.

Food sources of selenium include meat, vegetables, and nuts. The selenium content of the soil where food is raised determines the amount of selenium found in plants and animals. For adults, the recommended daily allowance for selenium is 55 µg /d.[2] Most dietary selenium occurs as selenocysteine or selenomethionine.[1] Selenium accumulates in the thyroid gland, liver, pancreas, pituitary gland, and renal medulla.[3]

Selenium is a component of the enzyme glutathione peroxidase, an enzyme that functions as an antioxidant.[4] However, at high concentrations, selenium may function as a pro-oxidant.[2]

    Next Article:

    Prostate Cancer, Nutrition, and Dietary Supplements (PDQ®): Complementary and alternative medicine - Health Professional Information [NCI] Topics

    Today on WebMD

    man with doctor
    Symptoms, risks, treatments
    man coughing
    Men shouldn’t ignore
    prostate cancer cells
    What does this diagnosis mean?
    doctor and male patient
    Is it worth it?
    cancer fighting foods
    15 Cancer Symptoms Men Ignore
    Prostate Enlarged
    Picture Of The Prostate
    Prostate Cancer Quiz
    screening tests for men
    Prostate Cancer Symptoms
    Vitamin D