Selenium, Red Blood Cells Unit Converter

Selenium, Red Blood Cells (RBC Selenium) measures the concentration of the trace mineral selenium inside your red blood cells. Because red blood cells live for about 120 days, this test reflects your selenium status over the past three to four months rather than a snapshot of recent intake.

Selenium is an essential trace element that the body incorporates into selenoproteins, a family of roughly 25 enzymes involved in antioxidant defense, thyroid hormone metabolism, and immune regulation.

Unlike serum selenium, RBC selenium is not affected by the acute phase response to inflammation, making it a more reliable marker in people with infections, chronic illness, or recent trauma.

Selenium is obtained entirely from the diet and is absorbed in the small intestine, then incorporated into selenoproteins throughout the body. It concentrates in organs with high metabolic activity, including the thyroid, kidneys, liver, and skeletal muscle, and is also stored within red blood cells.