Selenium (Serum) Test

What is Selenium?

Selenium is a trace mineral that is needed by the body in small amounts to maintain good health. Selenium is present in many foods, is available as a dietary supplement, and is accumulated by plants from the soil and ground water. In the body, it is stored mostly in the muscles. Selenium is a component of selenoproteins that form proteins and enzymes. Selenoproteins have a role in the production of DNA that carries our genetic information, and in the metabolism of thyroid hormones that maintain thyroid gland function. They are also involved in reproduction, and in protecting the body from infection and cell damage.

What is a Selenium test?

The selenium test measures the amount of selenium in blood serum. Selenium is released from food and/or supplements and passes into the bloodstream.

Can I buy a Selenium test online?

The Online Clinic offers serum Selenium testing. This can be via a self-collect blood sample using a specially designed kit for patients to use at home, or a professional blood draw in one of our partner pharmacies. Results take 4 days.

Selenium Test £69.95

Buy Now

Why is a Selenium test important?

A selenium test is used to investigate whether the body contains sufficient selenium to maintain good health. A deficiency or an excess level of selenium in the blood may cause health issues.

Both selenium and iodine are necessary for normal thyroid functioning. An excess of one of these essential minerals can lead to a deficiency of the other, thus increasing the risk of thyroid problems.

When selenium levels are too low, you may experience nausea/vomiting, tiredness, headaches, confusion, seizures, and coma. Selenium deficiency may be associated with several complications, including thyroid disorders, impaired immune function, fertility and reproductive problems, cardiovascular effects, musculoskeletal abnormalities, neurological symptoms, and cognitive decline. A type of heart muscle disease (called Keshan disease) and osteoarthritis (called Kashin-Beck disease) are associated with selenium deficiency.

When selenium levels are too high, you may experience nausea, diarrhoea, a metallic taste, tiredness, brittle nails, hair loss, tender muscles, irritability, heart attack, breathing problems and kidney failure.

Who should have their Selenium level tested?

The intake of selenium by most people in the UK is sufficient for good health. Individuals who have signs and symptoms indicating that selenium levels are too low or too high should have their blood selenium levels tested.

However, certain groups of people are at risk of a selenium deficiency and, thus, may have their selenium level tested. These include people:

who primarily eat a plant-based diet (e.g., vegans and vegetarians) and live in areas where the soil has a low selenium content (e.g., some parts of Russia and China, and some European countries).
living with HIV, possibly due to decreased appetite and inadequate selenium intake, diarrhoea, and/or poor selenium absorption.
with kidney failure who are undergoing dialysis, due to dietary restrictions decreasing food intake, and because dialysis removes some selenium from the blood.
with a high iodine level, because a high iodine level can lead to a deficiency of selenium, and increase the chance of abnormal thyroid functioning.
who have thyroid disease, because of the role of selenium in thyroid hormone production and its chemical processes. Notably, the thyroid gland has the highest selenium concentration in the body.
who smoke, as smokers generally have lower selenium levels than non-smokers, possibly due to an increasing level of harmful oxidative stress.

Individuals who are at risk of a selenium toxicity and, therefore, may have their selenium level tested include people:

who eat too many Brazil nuts every day, since only one nut contains more than the recommended daily amount of selenium.
wwho take supplements containing selenium at levels greater than the recommended daily amount.

How to test for Selenium?

Selenium testing requires a small blood sample, which you collect at home. You are provided with the test kit and full instructions on how to collect the blood sample. Testing is quick and simple. After cleaning, prick your little finger tip with the lancet. Collect the blood drops in the collection tube up to the top line printed on the side of the collection tube. If you need more blood to provide a complete blood sample, prick the other little finger tip. Place the cap on the collection tube and gently invert it between 5 and10 times. Fill in the collection tube label and stick it to the tube. Finally, put the collection tube in the packing wallet, and post. The laboratory analysing the blood sample will send the selenium test results to your doctor. The doctor will explain your results to you, and decide if more tests or treatment are needed.

How do I get my Selenium test results?

One of the doctors at The Online Clinic will publish your lab report on your Patient Dashboard along with an interpretation of the results. The lab report can be downloaded from your Patient Dashboard as a PDF.

What are normal Selenium test results?

The amount of selenium that a person needs per day depends on their age. The daily amount of selenium required steadily increases with age, starting at 15 mcg at birth to 6 months.

The Recommended Dietary Allowance (RDA) for adult women and men who 19 years of age and older is 55 micrograms daily. Women and teens who are pregnant require 60 micrograms a day, and those who are breastfeeding need 70 micrograms a day.

The Tolerable Upper Intake Level of selenium a day in adults aged 19 years and older (including pregnant and breastfeeding women) is 400 µg. This is the maximum daily amount that is unlikely to be harmful to health.

How to maintain normal Selenium levels

People usually get most of their selenium requirements from the food and drink they consume. Protein-rich foods are often the best sources of selenium, including Brazil nuts, seafood, meat, and poultry. Other sources include grains (e.g., oats, whole-wheat bread, rice), eggs, dairy products, beans, and lentils.

The amount of selenium in plant-based foods depends largely on the selenium-content of the soil, so varies greatly between geographic regions. However, the selenium content in animal products does not rely on the selenium content of plants that the animals eat; the animals’ body functions control their selenium levels and, generally, they are given feeds that are fortified with selenium.

Selenium-fortified foods and selenium-containing dietary supplements can be taken in cases of nutrient deficiency or when more of the nutrient is needed (e.g., during pregnancy).