Selenium | Se (blood)

General Information

Selenium is one of the microelements that protects the body from oxidative stress.

Approximately 25 selenoproteins (proteins containing a selenocysteine ​​residue) have been described in tissues and cells, classified as glutathione peroxidases, thioredoxin reductases, and deiodinases.

Selenium is a necessary cofactor of glutathione peroxidase. Glutathione-peroxidases are a family of enzymes that catalyze the degradation of organic hydrogen peroxides in the metabolic process and provide protection of proteins, lipids and nucleic acids from oxidizing molecules.

The antioxidant activity is similar to that of vitamin E. Thus, selenium deficiency is associated with a decrease in glutathione peroxidase activity, which leads to the production of free radicals and, as a result, cell membrane damage.

5′iodothyronine deiodinase is a selenoprotein (enzyme) involved in the conversion of peripheral thyroxine (T4) to triiodothyronine (T3).

Selenium helps modulate the effects of toxic metals in the body, such as arsenic (As), cadmium (Cd), mercury (Hg), silver (Ag), lead (Pb), and platinum (Pt). A daily preventive dose of selenium (50-200 ng/day) can prevent the clinical effects of these toxic metals.

Selenium deficiency causes myocardial damage and development of cardiomegaly (increased heart size). Cardiac cell damage is caused by loss of membrane integrity, followed by replacement of cardiomyocytes with fibrotic (connective tissue) cells. Selenium deficiency is also associated with other pathologies, such as: cataracts, osteoarthritis in children, nail deformities, growth disorders, and others.

Selenium intoxication can be caused by its overdose in the form of medicine, or its entry into the body in the form of industrial waste. In heavy industry, selenium is used in copper processing, semiconductor production, vulcanization, rubber production, and more.

Due to its antioxidant properties, selenium is not a teratogenic element.

When is a selenium study performed?

• Clinical signs of selenium deficiency
• Monitoring of selenium replacement therapy
• Diagnosis of selenium intoxication

Patient preparation - It does not require prior preparation

study sample – Venous blood

Reference limits and interpretation of results

Selenium reference limits depend on the age of the patient:

• Up to 4 months: 25-111 ng/L
• 5-10 months: 23-131 ng/L
• From 11 months to 1 year: 38-150 ng/l
• 2-5 years: 59-168 ng/L
• 6-12 years: 73-177 ng/L
• 13-18 years: 81-188 ng/L
• > over 18 years 93-198 ng/L

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High concentrations of gadolinium and iodine affect serum selenium levels. Accordingly, from the administration of drugs containing gadolinium and iodine

At least 96 hours of selenium research is not recommended.