Selenium is a trace element that is naturally present in many foods, added to others, and available as a dietary supplement. It is nutritionally essential for humans, is a constituent of more than two dozen selenoproteins that play critical roles in reproduction, thyroid hormone metabolism, DNA synthesis, and protection from oxidative damage and infection
Selenium tests are done to ensure one does not suffer from selenium deficiency, for men it also identifies infertility problems.
The test process is a normal blood test with no prior fasting required.
High levels of selenium in your blood, defined as a concentration of more than 100 micrograms per deciliter, causes selenosis.