Selenium

Selenium is a natural selenium food supplement optimal effectiveness and bioavailability. Its organic form (selenomethionine) obtained from yeast extracts presents a better absorption than traditional inorganic selenium supplements.

Essential to life, this essential trace element contributes, among other things, to fight against oxidative stress , maintain a normal immune function and to preserve the hair and nail health . It thus remains a weapon of choice in periods of fatigue and convalescence.

What is selenomethionine?

Selenomethionine is the The most abundant form of selenium in our diet . It focuses primarily on plants (cereals, soya, brewer’s yeast, etc.). Indeed, when they grow in soil rich in selenium, plants manage to capture this mineral and metabolize it into organic derivatives (1).

At the chemical level, selenomethionine corresponds to the selenium analogue of methionine , one of 22 proteinogenic amino acids. In other words, methionine shares the same molecular formula with selenomethionine, but has its sulfur atom substituted by a selenium atom . This biochemical proximity makes selenomethionine able to integrate certain proteins in the body , called selenoproteins . In this form, it can thus be stored permanently in tissues , particularly muscle, then released on demand to satisfy the needs of the body.

The replacement of methionine by selenomethionine in the structure of the protein does not induce any notable functional change, and would even present certain advantages. For example, selenium would offer, compared to sulfur, a additional protection against oxidative processes (3). Furthermore, during photochemical reactions, the carbon-selenium bond is more easily broken than that linking carbon to sulfur: selenomethionine therefore reacts better to the energy of the ultraviolet light (4).

What is the best form of selenium?

Let us first point out that the organic selenium chelated with amino acids (such as selenomethionine or selenocysteine) is better assimilated than inorganic selenium salts (like selenite or selenium sulfide) (5). Selenomethionine would display on average an absorption rate of around 90% , compared to 50 to 60% for inorganic forms.

To be fully bioassimilated, selenium supplementation should focus on a form naturally ingested through food . The L isomer of selenomethionine, better known as L-selenomethionine is the most represented on our plates (6). Perfectly adapted to human metabolism, it presents a high bioavailability and leads to a rapid increase in blood selenium level (7).

What are the benefits of selenium?

According to the claims authorized by the EFSA, selenium participates in:

• to maintaining a normal immune function : several studies demonstrate the role of selenoproteins in the activation, proliferation and differentiation of immune cells, but also in the modulation of immunity (8);
• to protect the oxidative stress cells : as a cofactor of glutathione peroxidase , a redox enzyme, selenium supports the neutralization of free radicals attacking cell membranes (9). Conversely, a selenium deficiency could exacerbate the toxicity of by-products of redox reactions;
• to maintaining a normal thyroid function : the thyroid is the organ containing the most selenium in the human body. This trace element regulates the synthesis of thyroid hormones, more specifically the triiodothyronine (T3) (10);
• to one normal spermatogenesis : selenium is notably involved in testosterone metabolism and sperm motility (11);
• to maintaining normal hair and nails : thanks to its antioxidant properties, selenium improves the shine and vigor of the hair (12). It also helps to sport beautiful and shiny nails.