Selenium is a trace element that is considered to fight disease. It acts as an antioxidant, blocking the rogue molecules known as free radicals that damage your DNA.

What are its health benefits?

Selenium is part of an antioxidant enzyme (called glutathione peroxidase) that protects your cells against environmental and dietary toxins, so it’s believed that it might help guard against everything from cancer and cardiovascular disease to cataracts, macular degeneration (a chronic eye disease) and strokes.

Reportedly, its other benefits could include the following:

  • Because selenium blocks free radicals, which scientists have linked to the signs of ageing, getting enough of this mineral could help to keep your skin youthful.
  • It also fights viral infections.
  • Selenium supplements may reduce the odds of prostate cancer. However, researchers say that selenium may increase the risk of non-melanoma skin cancer.
  • Studies suggest that a daily dose of selenium helps to reduce or slow the progression of HIV – however, note that researchers pointed out that selenium supplements are an adjunct therapy to HIV drugs (antiretrovirals, or ARVs), not a replacement for them. 

Do you have a deficiency?

A selenium deficiency is thought to increase your risk of cancer and is also associated with male infertility. If you regularly fall prey to viruses, you might be low on this mineral.

Find it in these foods

Selenium is naturally present in water and many foods, is added to foods and is also available as a supplement.

It can be found in the following foods:

  • Brazil nuts
  • Cashews
  • Walnuts
  • Fish (including tuna and sole)
  • Liver
  • Lean red meat

Recommended dietary allowance (RDA)

There isn’t an official RDA, but experts suggest between 50 and 70mcg per day for adults. Eating just two Brazil nuts a day is enough to fulfill this. Children will need less, so be sure to check supplementary dosages with your Clicks pharmacist first.

Know the overdose risks

Excessive intake of it may cause the following side effects:

  • Garlic odour on breath
  • Metallic taste in mouth
  • Hair and nail loss or brittleness
  • Nausea
  • Diarrhoea
  • Rashes
  • Lesions of the skin and nervous system
  • Fatigue
  • Irritability

Acute selenium toxicity resulting from taking, for example, poorly formulated over-the-counter products containing selenium, could cause the following symptoms:

  • Severe gastrointestinal and neurological symptoms
  • Acute respiratory distress syndrome
  • Myocardial infarction
  • Hair loss
  • Muscle tenderness
  • Tremors
  • Lightheadedness
  • Kidney failure
  • Cardiac failure

Note that studies have shown that taking high doses of selenium during pregnancy can cause birth defects. 

Ensure you discuss dietary supplementation with your Clicks pharmacist to avoid the potential for side effects and adverse interactions with medications.

The accuracy of this information was checked and approved by Clicks' pharmacist Waheed Abdurahman in February 2015