Selenium is an essential micro-nutrient. Dietary levels vary widely, depending on both diet and location. In some regions, soil selenium levels are low, particularly in Europe, UK and parts of Asia. Deficiency contributes to many diseases.

Optimum intake has huge benefits, particularly for the ageing population, as selenium protects against a number of degenerative conditions. Optimum intake generally requires supplementation.

Dose is critical. Too much can be toxic, especially if taken over a long period. There is only a small difference between not enough, and too much.

Selenium Benefits

Selenium may protect against

  • Cancer (incl. colorectal, lung, bladder, prostate, stomach, liver) especially in selenium-deficient individuals
  • Cardiovascular disease (including atherosclerosis and heart attacks)
  • Cognitive decline
  • Neuro-degenerative diseases (including Alzheimer’s, Parkingson’s and Huntington’s)
  • DNA damage
  • Stroke-induced brain damage
  • Age-related decline of immune system
  • Many different virus infections

Selenium enhances

  • Immune system
  • Mood
  • Fertility
  • Thyroid function
  • Longevity

Selenium dosage

National Academy of Medicine:

Recommended Daily Allowance for adults: 55 mcg (pregnancy 60 mcg, lactation 70 mcg)

Upper Limit for adults: 400 mcg

Typical daily intake from food:

30 – 120 mcg depending on diet and region

Our supplementation recommendation for adults:

For men: 100 to 300 mcg per day

For women: 50 to 200 mcg per day

Selenium from all supplements (including multivitamins etc.) should be taken into consideration.

Selenium Caveats

If under medical care, discuss your intended dose of selenium with your doctor. (There may be medical reasons why you should supplement more or less than our recommended amounts.)

Excess selenium is toxic – early signs are

  • Garlic breath
  • Metallic taste in mouth
  • Nausea
  • Brittle nails or hair
  • Loss of nails or hair

If you experience any of these symptoms, discontinue selenium supplementation.

Selenium Science

For more detailed information about the importance of selenium in the diet, please see our resources list at the end of this page.

Selenium Supplements

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Selenium Resources

Selenium-Health Professional Factsheet

Current Knowledge on the Importance of Selenium in Food for Living Organisms

The Influence of Selenium on Immune Responses