Selenium is a trace mineral found naturally in the soil (type: selenium & selenide), water (type: selenite & selenate) and food sources.  It is an essential component of animal organisms and occurs in all cells. Most selenium is found in the kidneys, pancreas and liver. 


Selenium is an extremely vital mineral for the human body:

  • as an antioxidant protects cell membranes against the generation of free radicals – mutation and DNA damage
  • increases the quality of blood flow, therefore enhancing the body’s resistance against diseases and stress   
  • fights inflammation      
  • lowers chance and prevents coronary heart disease       
  • it is needed for the proper course of all metabolic processes      
  • it is very important for the functioning of the immune system
  • it is necessary for proper growth     
  • is essential for successful male and female fertility and reproduction     
  • selenium has a synergistic effect with other antioxidants like Vitamin E, enabling the body to fight oxidative stress & reduce the risk of cancer( specifically the liver, prostate, colon and lung cancer)     
  • also help to slow down existing cancer progression and tumor growth·     
  • helps with autoimmune disease and regulates thyroid function·     
  • antiviral effects
  • helps reduce asthma symptoms
  • helps with arthritis condition
  • it plays an important role in the transmission of nerve impulses in the central nervous system·     
  • increases longevity 

Lack of selenium in your body might cause: anemia, irregular heart bit, dandruff, sagged skin, premature aging, generally reduced immunity and weakening of the body.

Selenium in Food sources 

Did you know that, the amount of selenium is largely dependent on soil conditions that the food grew in? Ups…Therefore even within the same food, levels of selenium can vary widely. Selenium benefits may be found in crops grown in certain locations more so than others.  

Natural food sources that are high in selenium and best to consume are: 

  • brazil nuts ( high in source!)                   1 cup = 607 mcg!!!
  • eggs                                         1 medium egg =  146 mcg      
  • sunflower seeds                                      1 cup = 105 mcg      
  • chia seeds                                                 28g = 15.5 mcg     
  • lamb or beef liver                                         85g = 99 mcg      
  • chicken breast                                              85g = 33 mcg      
  • turkey                                                           85g = 25 mcg      
  • salmon                                                         85g = 31 mcg      
  • tuna / rockfish                                              85 g = 64 mcg      
  • halibut                                                          85 g = 47 mcg      
  • sardines in oil                                               85 g = 45 mcg      
  • mushrooms                                                 1 cup = 15 mcg      
  • cottage cheese                                   1 cup (1%) = 20 mcg      
  • some grains (brown rice)                            1 cup = 19 mcg

Selenium benefits – work best, when levels are met through eating selenium-rich foods, like the one stated above. If you already consume a proper amount of healthy food, supplementation on selenium might not be beneficial. You should always consult with a doctor before reaching for Selenium supplementation. 

The recommended daily allowance (RDAs) for selenium depends on your age and is as follows:

Birth to 6 months                              15 mcg (micrograms)/day

7- 12 months                                                             20 mcg /day

Children 1–3                                                              20 mcg /day

Children 4–8                                                            30 mcg /day

Children 9–13                                                           40 mcg /day

Adults and children 14 and up                              55 mcg /day

Pregnant women                                                    60 mcg /day

Breastfeeding women                                           70 mcg /day

Interaction with other medicine

Selenium may also interact with other medicines and supplements. These include:

  • antacids (medicines that counteract (neutralize) the acid in your stomach to relieve indigestion and heartburn
  • chemotherapy drugs
  • corticosteroids
  • niacin (Vitamin B3)
  • cholesterol-lowering statin drugs
  • birth control pills

If you take any of these medications, always speak with your doctor before supplementing with selenium.

Precautions and possible side effects of High Level of selenium

The toxicity of most forms of selenium is rare and usually only experienced in people who supplement with high levels of selenium.  Too high levels of selenium can lead to poisoning or toxicity, and this can potentially be fatal or lead to heart attack and respiratory (lung) depression. 

An overdose of selenium may possibly cause reactions like:     

  • bad breath
  • fever
  • nausea
  • potentially liver complications — or even kidney and heart problems — although these only occur at very high levels of selenium that reach ‘’poisoning’’ status.