Selenium

What is Selenium?

Selenium is an essential trace mineral that plays a crucial role in the functions of the human body. It is a potent antioxidant that primarily acts through selenoproteins, making it important for protecting cells against oxidative stress. Selenium is also necessary for proper thyroid function and the immune system, as well as for maintaining sperm quality in men.

How does it work in the body?

In the body, selenium functions as part of several selenoproteins, which are important for regulating antioxidant activity, metabolism, and immune response. These proteins help neutralise free radicals, reducing the risk of cell damage and age-related diseases. Selenium is also involved in the production of thyroid hormones, which are essential for the body's metabolism and energy levels.

Scientific benefits

Several studies have documented the health benefits of selenium. According to research published in the Journal of Nutrition, selenium has been shown to support the immune system and reduce inflammation. Additionally, studies have demonstrated that adequate selenium levels may be linked to improved sperm quality and fertility in men. A meta-analysis in Nutrition Reviews also indicated that selenium may have a protective effect against certain types of cancer, particularly prostate cancer.

Dosage and recommendations

The recommended daily intake of selenium varies depending on age and sex. For adults, the recommended dose is approximately 55 micrograms per day. Pregnant and breastfeeding women have a slightly higher requirement, around 60-70 micrograms per day. It is important not to exceed the upper limit, which is 400 micrograms, as high doses can lead to selenium toxicity.

Best sources and forms

Selenium is found in many foods, and the best sources include:

• Brazil nuts – one of the richest sources of selenium.
• Seafood – such as tuna and shrimp.
• Meat – especially beef and chicken.
• Whole grain products – such as brown rice and oats.
• Eggs – a good source of selenium and protein.

Selenium is also available in dietary supplements, usually in the form of sodium selenite or selenomethionine. It is important to choose high-quality supplements to ensure proper dosing.

Side effects and warnings

Exceeding the recommended intake of selenium can lead to side effects such as hair loss, gastrointestinal issues, and in severe cases, selenium toxicity. Symptoms of selenium toxicity may include nausea, diarrhoea, fatigue, and a metallic taste in the mouth. It is always important to consult a doctor before starting supplements, especially if you have underlying health conditions.

Frequently asked questions

What are the main functions of selenium in the body?

Selenium acts as an antioxidant, supports thyroid function, enhances the immune system, and affects sperm quality.

Can I get enough selenium through diet?

Yes, most people can obtain sufficient selenium through a balanced diet rich in nuts, seafood, meat, and whole grain products.

Is selenium good for the skin?

Yes, selenium has antioxidant properties that can protect the skin from damage caused by UV rays and pollution.

Can selenium help with depression?

Some studies suggest that selenium may have a positive effect on mood and reduce symptoms of depression, but more research is needed to confirm this.

Is it dangerous to take too much selenium?

Yes, overdosing on selenium can lead to serious side effects and selenium toxicity, so it is important to follow recommended dosages.