Learn about selenium and if it's safe.

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About selenium

Selenium occurs naturally in the environment. It is found in the earth's crust and in some minerals.

It can also be found in common natural health products, such as:

  • anti-dandruff shampoos
  • multi-vitamin and mineral supplements

Selenium is found in foods, including:

  • nuts
  • fish and seafood
  • cereal products, such as:
    • flour
    • grains
    • breads
    • baked goods
  • organ and muscle meats, such as:
    • liver
    • heart
  • some traditional Indigenous foods, such as marine mammals

Safety of selenium

Selenium is an essential nutrient for human health. Most Canadians get the selenium they need from following a healthy eating pattern.

We assessed the potential health and environmental risks of selenium through a chemical risk assessment.

We found that fish caught near mining operations may have higher selenium levels.

We also found that:

  • consuming multi-vitamin or mineral supplements containing more than 200 micrograms of selenium a day may be a health risk
  • high selenium levels may be a risk to some groups in northern Canada
    • however, there is no evidence that eating traditional food rich in selenium is harmful to our health

Overexposure to selenium

Exposure to high levels of selenium may cause:

  • hair loss
  • muscle weakness
  • garlic odour in breath
  • reduced brain function
  • nail loss and deformities
  • stomach and intestinal disorders

Ongoing protective measures

To protect Canadians from being exposed to too much selenium, we plan to:

  • continue to regulate selenium in:
    • food
    • drugs
    • cosmetics
    • pesticides
    • natural health products
    • surface and paint coatings
  • lower the maximum daily dose of selenium allowed in natural health products, such as multi-vitamin and mineral supplements
  • continue to regulate the release of selenium into water from:
    • agriculture
    • wastewater
    • coal and metal mining
    • base metals smelting and refining
    • power generation industrial sectors
  • research and monitor selenium and act quickly if a product is a risk to consumers

Minimize your exposure to selenium

To minimize your exposure to selenium:

  • read product labels and follow safety precautions
  • follow label directions to dispose of products properly
  • take only multi-vitamin or mineral supplements that have a Natural Product Number (NPN) on the label
  • do not exceed more than 200 micrograms of selenium a day when taking multi-vitamin or mineral supplements

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