Selenium is an essential trace mineral required for normal function of the body and metabolism. Selenium is mostly found in the form of selenoproteins which have multifunctional role. Its daily requirement to human body is minimal however excessive amount may lead to selenium toxicity. Selenium deficiency may lead to several health conditions like, cardiovascular disease, impaired immunity and metabolism, infertility and cognitive decline. 

Functions of Selenium

The available form of selenium in human body is selenoproteins which is essential for the proper functioning of the body. Selenium acts as cofactor to the enzymes responsible for deiodination of thyroid hormone. It also cats as antioxidants and crucial in expulsion of free radicals from the body. In addition to this selenium deficiency affects the immunity system and progression of HIV to AIDS.

What is Selenium Deficiency?

Selenium deficiency is caused by the prolonged deprivation of selenium intake which may primarily be caused by unavailability of selenium rich diet and secondly, the malabsorption due to presence of certain health conditions like phenylketonuria & gastrointestinal disorders.  

Selenium works as antioxidants along with vitamin E to remove free radicals from the body. Its deficiency can cause impaired immunity, impaired wound healing and very rare disorders like Keshan disease and Kashin-Beck disease.

Causes of Selenium Deficiency

The condition of selenium deficiency can be developed due to various factors. Some of the major cause have been illustrated below:

  • Inadequate Diet: The long-term deprivation of selenium rich diet is the common cause of its deficiency. The major source of selenium is animal produce that rely on selenium rich plant diet. The availability of selenium rich food item is scarce in certain regions. 
  • Unavailability of Nutritious Food: Selenium deficient soil can be another cause of availability of selenium deficient food item. It occurs in different geographies and can be resolved with selenium rich fertilisers and fortified seeds.
  • GI Disorders: Selenium is mostly stored in in the form of protein. However, its absorption is affected by the gastrointestinal surgeries like bariatric surgeries. It can also be cause by the small intestine tract infections.

In addition to the major causes mentioned above, selenium deficiency can also be caused by the phenylketonuria.

Symptoms of Selenium Deficiency 

The common symptoms of Selenium deficiency include:

  • Weakness
  • Fatigue
  • Muscle weakness
  • Hair loss
  • Infertility
  • Impaired Immunity
  • Thyroid

Health Risks due to Low Selenium

  • Keshan Disease: Keshan disease is associated with selenium deficiency. It is very rare heart disease which causes heart failure, heart enlargement, abnormal electrocardiogram, heart rate abnormalities and even cardiac shock. It is generally observed in pregnant women and children with morbidity rate of more than 50%.
  • Impaired Thyroid Regulation: Selenium acts as cofactors of the enzymes responsible for deiodination. The conversion of inactive thyroid (T4) to active thyroid (T3) depends upon the presence of selenium in the body. 
  • Impaired Immunity: Selenium deficiency compromises the immunity. It can lead to immune deficiency diseases like AIDS and. Impaired wound healing and frequent infections are another outcome of selenium deficiency.  
  • Free Radicals: The metabolism activity constantly releases free radicals due to oxidation however, in can be removed by the presence of micronutrients with antioxidants properties. Selenium works in the association of vitamin in removing free radicals from the body. 
  • Male Infertility: Selenium is essential for biosynthesis of testosterone in the body and affects the production of normal sperm. Large concentration of selenium is present in testicular tissues and its deficiency affects male fertility.
  • Cognitive Impairment: It has been observed that selenium deficiency may lead to very rare cognitive disorders like Kashin-Beck disease.

The effect of selenium with reference to cancer is being studied however there is not much success in this field.

Tests for Selenium Deficiency

Selenium is the trace mineral present in body. It is mainly available as cofactor with several proteins and enzymes. 

  • Glutathione Peroxidase: It’s very difficult to diagnose selenium deficiency because there isn’t any test available for it. However, in several cases the level of glutathione peroxidase, a selenoproteins is measured to identify the deficiency of selenium.

However other indirect methods like scalp hair and nails are used for the identification of selenium deficiency.  These methods are more convenient than the serum test.

Remedies of Selenium Deficiency 

  • Selenium Supplements: The clinical remedies of selenium deficiency are to take selenium supplements. If you are diagnosed with severe Selenium deficiency, you should consider medical supplements under supervision of doctors. As higher Selenium may lead to selenium toxicity.
  • Selenium Rich Diet: The simple way to prevent selenium deficiency is intake selenium rich food items in daily diet. Some of the selenium rich food items are nuts, sardines, ham, pork, beef, turkey, chicken, fish, shellfish, and eggs.
  • Fortified Food Items: Several agricultural lands across the globe are poor in micronutrients which produces nutrient deficient food items. It can be overcome by selenium rich fertilizers and fortified seeds. 

Prevention of Selenium Deficiency

It is often said that “Prevention is better than Cure” and indeed this is very much true with reference to micronutrient deficiencies. Selenium deficiency can be prevented through consumption of Selenium rich diet.

Food items rich in selenium:

  • Nuts
  • Sardines
  • Ham
  • Pork
  • Beef
  • Turkey
  • Chicken
  • Fish
  • Shellfish
  • Eggs
  • Seeds
  • Mushroom

 Adequate Intake (>19 yrs.):

Simple way to prevent Selenium deficiencies is to maintain recommended daily intakes. The intakes of selenium vary with the different age groups however, the recommended daily intake of selenium for an adult is 400 micrograms.


Selenium is essential trace mineral require to performs multifactorial roles for the proper function of the body. It acts as cofactor for several proteins and enzymes responsible for regulating endocrine system, male fertility and improved immunity. Selenium deficiency causes rare diseases like Keshan which is related to function of heart and Kashin-Beck disease which is associate with cognitive impairment.  

Although Selenium deficiency has several ill effects, it can be treated with the right consultation and medical supplements as prescribed by medical experts however, high concentration of selenium may be deadly. The best possible way to avoid these complications by consuming adequate amount of Selenium as per RDA through various Selenium rich diet.