[Selenium and health; reference values and current status of Spanish population].

Selenium (Se) has gone, in a few years, from being considered only a toxic element to attribute it remarkable benefits for the human health: from antioxidant and hormonal regulations of thyroid functions to established anti-carcinogen effects. The Se is an essential microelement for humans and livestock, but not for plants, which extract it from soil incidentally. Therefore the population Se status of a area ultimately depends on its presence in soil. In the last two decades have shown that the individual Se requirements are higher than the values referenced given for Official Organism, and that should be considered not only the direct effects of deficiency, but adequate to achieve optimal health through maximize/ optimize the Se-proteins. In Spain, the few studies on healthy people show low Se levels in blood. This fact is corroborated by the low Se concentration on the main food groups. The cereals, more specifically wheat and derivative products, is one of main groups that provide greater Se contribution to the diet. However, the wheat Se concentrations in Spain are low, partly explaining the low blood levels found in the Spanish population. It would need to involve the National Public Organizations to increase the number of studies of this subject, in order to elucidate the extent of Se deficiencies in Spanish population and to evaluate possible solutions.