Selenium, an essential trace element, is a crucial component of selenoproteins, which are involved in various bodily functions. These functions include antioxidant activity, thyroid hormone metabolism, and immune system defense. Monitoring selenium levels provides insights into an individual’s nutritional status and potential health concerns.
Reasons for Testing Selenium Levels
Healthcare providers may recommend selenium level testing when a person exhibits symptoms that could indicate either a deficiency or an excess of this trace element. Signs of insufficient selenium can include fatigue, muscle weakness, hair loss, and a compromised immune system. Thyroid dysfunction, cognitive issues, and even infertility may also be associated with low selenium levels.
Conversely, an excess of selenium, known as selenosis, can manifest with distinct symptoms. These may include a garlic-like odor on the breath, a metallic taste in the mouth, and gastrointestinal disturbances. Hair loss, brittle nails, and fatigue are also common indicators of selenium toxicity. Testing is typically initiated by a doctor to help determine the underlying cause of these symptoms.
Methods for Testing Selenium
Several methods are available for assessing selenium levels, each providing different insights into the body’s selenium status. Blood tests are a common approach, with distinct types used depending on the information sought. Serum or plasma selenium measurements reflect recent dietary intake and short-term selenium status.
Whole blood or red blood cell (RBC) selenium tests offer a view of longer-term selenium status, reflecting levels over approximately two to four months. These tests can indicate the amount of selenium stored in tissues and are less influenced by acute illness or inflammation.
Urine tests measure the amount of selenium excreted from the body, which can be useful for assessing recent exposure or confirming toxicity. A 24-hour urine collection is often used to provide a comprehensive picture of selenium excretion over a full day. Hair and nail analyses can also be performed to evaluate long-term exposure to selenium, reflecting status over several months or even years. However, these methods have limitations for clinical diagnosis compared to blood or urine tests.
Understanding Your Selenium Test Results
Interpreting selenium test results involves comparing the measured levels to established reference ranges. These “normal” ranges indicate the typical concentrations found in a healthy population. For instance, serum selenium levels in adults are generally considered to be within a range of 70 to 160 micrograms per liter (µg/L) or 70 to 150 nanograms per milliliter (ng/mL). However, it is important to understand that specific reference ranges can vary between different laboratories.
Results falling below the established reference range typically indicate a selenium deficiency. Conversely, levels that exceed the upper limit of the reference range suggest an excess, or potential toxicity. Since individual factors can influence these levels, a healthcare professional must interpret all test results. They will consider your symptoms, medical history, and other relevant information to provide an accurate assessment.
Addressing Selenium Imbalances
When selenium levels are found to be outside the normal range, specific approaches are taken to restore balance. For individuals with low selenium levels, increasing dietary intake of selenium-rich foods is often the first step. Excellent natural sources include Brazil nuts, seafood, lean meats, poultry, eggs, and certain grains.
In some cases, a healthcare provider may recommend selenium supplementation to correct a deficiency. Supplementation should always be done under medical guidance, as excessive intake can lead to adverse effects. Conversely, if test results indicate high selenium levels, the primary approach involves reducing intake from dietary sources or discontinuing any selenium supplements. It is important to consult with a healthcare provider for personalized advice and ongoing monitoring to safely manage any selenium imbalance.