What Makes Selenium an Essential Antioxidant?

Selenium—an often overlooked trace element that can have a huge impact on your body. Whether it’s for a strong immune system, thyroid function, or protecting your cells from oxidative stress, selenium is a true multitasker. But are you getting enough? And what does soil quality in Europe have to do with it? Find out why selenium is so important and which foods are particularly rich in it.

What is selenium, and why is it important?

Selenium, often referred to as selenium, is one of the many minerals your body needs. Because only small amounts are required, it’s considered a trace element and, due to one of its unique functions, also an antioxidant. It’s also a vital nutrient, making it an all-rounder. Since our bodies can’t produce this essential mineral, we need to obtain it through our diet.

In the body, selenium’s effects are diverse. It’s long been known as a secret weapon against free radicals, acting as an antioxidant to help your cells fend off harmful environmental substances. As a component of 25 enzymes in your body, selenium plays a crucial role in keeping your bodily functions running smoothly.

Why do we need this trace element?

In its antioxidant role, selenium helps neutralise harmful substances like alcohol, nicotine, environmental toxins, or excessive sun exposure in your cells. This is particularly true for immune cells, making selenium key to a strong immune system. Neutralising free radicals also supports overall cell performance, especially important for brain health, as free radicals can hinder oxygen supply to the brain. In the brain, selenium plays a vital role in producing neurotransmitters and serotonin, the so-called “happiness hormone.”

In addition to iodine, selenium is an essential trace element for the thyroid, contributing to hormone production and regulation that’s critical for the proper functioning of most organs.

As a component of enzymes, selenium also supports protein synthesis, which is essential for healthy skin, hair, and nails. Selenium is also a key player in an enzyme essential for fertility, forming part of sperm and contributing to reproductive health.

How much selenium do I need daily?

The German Nutrition Society (DGE) recommends the following daily intake:

• Male adolescents aged 15 and older, and adult men: 70 micrograms
• Female adolescents and adult women: 60 micrograms
• Children up to age 14: 10 to 60 micrograms
• Infants: 10 micrograms

Breastfeeding women should aim for 75 micrograms per day.

Where can I find selenium in food?

Selenium is found in soil and, from there, enters plant-based foods. The concentration depends on the selenium content of the soil where the plants are grown. In Europe, soils are generally low in selenium, meaning animal-based foods often provide better selenium intake. If you follow a vegan diet, focus on fruits and vegetables that are high in selenium. The following foods contribute to an adequate intake of selenium:

• Meat
• Dairy products
• Eggs
• Fish, especially tuna
• Brazil nuts
• Coconuts from South America
• Cruciferous vegetables
• Mushrooms and porcini
• Oats
• Walnuts
• Brown rice
• Potatoes
• Dried lentils

Soils in the United States are much higher in selenium, so plant-based foods grown there tend to contain more. Specifically, for Brazil nuts—known for their high selenium content—the Federal Office for Radiation Protection recommends eating no more than two nuts per day due to high levels of radioactivity.

What symptoms can indicate a selenium deficiency?

In general, a balanced diet provides sufficient selenium. However, a deficiency may arise from a limited diet based solely on locally sourced plant products or from disruptions in selenium metabolism. Typical symptoms include:

• Increased susceptibility to infections
• Muscle function impairment
• Reduced sperm production
• White spots on nails
• Thin, dull hair
• Pale skin

If you notice signs of a selenium deficiency, it’s wise to consult your doctor.

Can selenium supplements offer health benefits?

Selenium supplements can be useful if you can’t meet your daily needs through diet alone. This might be the case with a vegan diet that relies solely on local produce. Certain underlying conditions can also disrupt selenium metabolism. Before taking selenium supplements, it’s best to speak with your doctor. They can help identify any potential selenium deficiency causes and offer appropriate solutions.

Too much selenium can cause symptoms similar to a deficiency. The European Food Safety Authority recommends a maximum daily intake of 300 micrograms for adults. Most supplements contain no more than 200 micrograms, so if taken as directed, there’s little risk of overdosing.