Red cell selenium blood test in Chiswick

What the test measures

Selenium is a trace mineral used to make selenoproteins, which help protect cells from oxidative damage and are essential for producing active thyroid hormone. It comes from Brazil nuts, fish, eggs, meat and wholegrains. The selenium content of plant foods depends on the soil, and UK soils are relatively low in selenium.

Red cell selenium measures the selenium taken up by red blood cells as they form. Because these cells circulate for about three to four months, the test reflects a longer period than plasma or serum selenium, which mainly shows recent intake. It is a complementary measure rather than a standard NHS test.

The price includes the sample taken at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review of your result, and a GP feedback report on request.

Who it is for

• You eat a vegan or highly restricted diet and want to check longer-term selenium intake.
• You have a digestive condition or have had surgery that affects absorption.
• You take selenium supplements and want to make sure you are not taking too much.
• You have a thyroid condition and want to discuss your selenium status with a practitioner.
• You have had a serum selenium result and would like a longer-term view.

Understanding your result

Your report shows your red cell selenium level and the laboratory reference range. A low result may reflect low dietary intake or poor absorption over recent months. A high result most often reflects supplement use, and very high intake can cause selenium toxicity, with symptoms such as hair loss, brittle nails and a garlic smell on the breath.

Your practitioner will read the result together with your diet, supplements and any thyroid results. A result outside the range is a prompt for discussion rather than a diagnosis.

Preparing for your test

Fasting is not required. Please tell us about any selenium, multivitamin or thyroid supplements and how many Brazil nuts you eat regularly, as just a few can contain a large amount of selenium. Any additional steps will be explained when you arrange your appointment.

Selenium supports thyroid hormone production, so our thyroid blood tests can add useful context. A standard serum selenium test is also available. For broader nutrition, see Nutritional and Digestive Health or every blood test and price in Chiswick.

Questions

How much is a red cell selenium test in Chiswick?

The Red Cell Selenium test costs £99. This covers the blood sample at our Chiswick clinic, analysis at the Randox accredited laboratory, a practitioner review of your result, and a GP feedback report on request.

How is red cell selenium different from serum selenium?

Serum selenium mostly reflects recent intake. Red cell selenium gives a longer-term view across the life of the red cells.

Can I have too much selenium?

Yes. Taking high-dose supplements or eating large numbers of Brazil nuts can lead to excess selenium. The NHS suggests most people can get enough from their diet.

Does selenium affect my thyroid?

Selenium is needed to convert thyroid hormone into its active form. Your practitioner can explain how your result fits with any thyroid tests.