Selenium, RBC details

Selenium is a trace mineral your body needs for antioxidant enzymes, thyroid hormone metabolism and immune function. This test measures selenium inside your red blood cells. Because red cells live for about four months, the result reflects your selenium status over a longer period than serum selenium, which changes more quickly with recent diet. A lower result can point to low intake, poor absorption or long-term nutrition support without enough selenium. A higher result usually reflects high intake from supplements or selenium-rich foods such as Brazil nuts, and very high levels can be toxic. It is interpreted alongside your diet, supplements and other selenium tests.