There are very few reports on the average serum selenium levels in Indian. However, two recent studies in China and Germany reported that low serum selenium status was associated to COVID-19 mortality.
In the present study, relatively younger patients with mild symptoms were analysed, unlike in the German study, wherein patients were older and had more severe symptoms.
“All these factors prompted us to carry out this exploratory study,” said Shaheen Majeed, President of Sabinsa.
The study was conducted by Sami-Sabinsa Group which researches and manufactures dietary supplements, herbal extracts and cosmeceuticals, and published in the Nutrition journal.
Selenium is an essential mineral for the defence against viral infections. Viral infections cause oxidative stress which leads to increased damage.
Majeed told NutraIngredients-Asia he always believed that selenium is an important supplement to fight viral infections.
“An association between selenium status and viral infection has long been known to exist.
Selenium deficiency has been associated with increased incidence, severity, and progression of several viral infections, like influenza, and HIV infections. Dietary selenium deficiency causes oxidative stress in the host. This can alter a viral genome, so that a normally benign or mildly pathogenic virus becomes highly virulent in the deficient host under oxidative stress.”
Selenium is found naturally in foods grown in soil, such as vegetables, lentils, and nuts.
The study analysed blood serum levels in 30 healthy individuals (control) from the population, and 30 patients with COVID-19 infection from Apollo Hospital Chennai and Vagus Hospital Bangalore.
Subjects were between 18 to 45 years old. Infected patients had fever but were otherwise stable, and not on ventilator support.
Blood samples and 24-hour urine samples were collected from all participants.
Selenium in COVID-19
The COVID-19 patients had significantly lower selenium levels of 69.2 ng/mL than controls 79.1 ng/mL (p<0.0003).
According to Majeed, selenium strengthens the immune system by increasing the proliferation of natural killer cells and improves T cell response.
“Selenium also reduces the formation of thrombosis in the blood vessels. Blood coagulation disorders leading to the formation of micro-clots are a significant cause of death in patients with COVID-19.”
In in-vitro studies, selenium was also found to reduce viral replication, transcription and life cycle. “Selenite also inactivate key proteins involved in apoptosis (Caspase3) and inflammation (nfkB), thus preventing cell death and inflammation, a common feature in COVID-19,” Majeed added.
Selenium in general population
In addition, researchers found that selenium levels in the general healthy population fell below the optimal levels needed to strengthen the immune system.
About 43% of patients with COVID-19 had lower selenium levels compared with 20% of the control group.
Majeed said: “We observed that the mean levels in control individuals were only 79.1 ± 10.9 ng/mL, which is much lower than the optimum required levels, suggesting a general deficiency of this micronutrient in the population studied. Urine samples did not show detectable values of selenium.”
The normal range for serum selenium is between 70 to 150 ng/mL, varying in countries, however, a minimum level of 98.7 ng/mL was suggested by several studies in Europe and Middle East to optimise selenium’s mechanism.
While selenium deficiency itself does not usually cause illness, but rather makes the body more susceptible to illnesses, it is reported to affect between 500 million to 1 billion people worldwide, due to inadequate dietary intake.
There are currently no specific therapeutic drugs recommended for the treatment of COVID-19, although there are many clinical studies on vitamins, minerals, alternative medicines to support recovery of patients or reduce severity of symptoms.
Recently, researchers in Europe and Africa have outlined a supplementation action plan for COVID-19 patients.
Majeed believes its supplementation could also be valuable during the vaccination program as selenium is involved in a protective immune response which is vital even during vaccination.
Apart from selenium, Majeed said zinc and vitamin D may be useful to fight against COVID-19.
In addition, “There are several herbs that may be important to build immunity and also to reduce the complications induced by infection, such as curcumin and ashwagandha.”
The results of this exploratory study pave the way for further research in a larger population and suggest that selenium supplementation may be helpful in reducing the effects of the virus in India and worldwide.
Sabinsa currently manufactures a selenium ingredient called Selenium SeLECT, in its most bioavailable form (L-selenomethionine).
“An exploratory study of selenium status in healthy individuals and in patients with COVID-19 in a south Indian population: The case for adequate selenium status”
Authors: Muhammed Majeed, et al.