Selenium is one of the essential trace elements which have a crucial influence on the function of the human body. It stimulates the maintaining of a normal hair and nail condition, a standard functioning of the immune system, the thyroid activity and protects body cells from oxidative stress. And it is of an extra importance for men – by promoting a normal spermatogenesis, i.e. the production of sperm. We obtain selenium naturally as part of our diet (nuts, intestines, fish and sea algae), however, thanks to up-to-date technologies, there is yet another source of organic selenium, the so-called selenium yeast. It is a conventional yeast (Saccharomyces cerevisiae microorganisms), which is cultivated in selenium enriched media. They absorb such selenium and transform it to selenomethionine during their growth. This type of selenium can be absorbed in a much easier way by the human body bringing it a maximum benefit. We have applied selenomethionine for instance in our HAIR & NAILS dietary supplement.