Selenium accumulation in plant foods.

Selenium (Se) is an essential nutrient, and Se deficiency is associated with disease conditions and general impairment of the immune system. Supplementation of Se to humans already consuming the RDA may help to prevent certain cancers. A convincing argument can be made for augmenting the food supply with Se, and Se-enhanced plants may be the best means of accomplishing this. Plants accumulate varying amounts of Se in different chemical forms; some plants accumulate Se in direct relationship to the amount available from the soil, whereas others (Se-accumulators) may accumulate Se in concentrations many orders of magnitude above that in the soil. There are many different chemical forms of Se in plants, and the form partially dictates the metabolism of Se by the animal that consumes the plant. The Se content and the chemical form of Se within plants may be altered by manipulation of plant genetics or by agricultural production conditions. However, attempts to maximize Se in plants may have unintended consequences and must be carefully monitored.