The capability of yeasts for binding magnesium in the amounts exceeding its physiological demand affords an opportunity for exploiting those organisms as a natural source of a deficient bio-compound in a diet of contemporary humans. The mechanism of cation binding with yeast cells demonstrating first the character of chemisorption followed by intracellular bioaccummulation, may lead to the formation of organic linkages called “bioplexes”. Magnesium ions bound with proteins in the form of the so-called “bioplexes” are very well assimilated by human and animal organisms, thus they may be an alternative to pharmacological supplementation at increasingly observed magnesium deficiency. After appropriate treatment, reducing the content of nucleic acids, cellular biomass of yeasts may not only be a valuable source of protein and vitamins but also of magnesium, especially when used in the form of protein-mineral preparations.