Selenium

Selenium (Se) is a trace element essential for the function of various body systems. It is particularly important for thyroid function as it is involved in the conversion of thyroid hormones – T4 (thyroxine) into the more active form T3 (triiodothyronine). Additionally, selenium supports normal immune system function, is essential for spermatogenesis, helps maintain healthy hair and nails, and protects cells from oxidative damage by acting as an antioxidant.

Determining selenium levels in serum is used to assess body reserves and is especially important for patients on long-term parenteral nutrition, as selenium is often omitted from nutritional compositions. Insufficient selenium levels can lead to weakness, muscle pain, and weakened immunity, and in severe cases – cardiomyopathy. In some parts of the world, due to soil characteristics, both selenium deficiency and excess may be diagnosed.

Test principle: Selenium concentration is determined in plasma or serum, usually by spectrometric methods. Results are presented in micrograms per liter (µg/l).

Recommendations:

• Recommended for patients undergoing long-term parenteral nutrition.
• Useful in cases of suspected trace element imbalance, especially with immune system, hair, or nail problems.
• Assigned for evaluating oxidative stress conditions, infertility, and thyroid dysfunctions.
• The test may be useful in endemic areas where the selenium content in food is very low or very high.
• It is recommended to come for the test fasting and to avoid selenium supplements for at least 24 hours before the test.