Baker's yeast (Saccharomyces cerevisiae-Sz1) enriched in chromium, iron, selenium or zinc was prepared by shaken cultivation and laboratory fermentation. Determination of the cellular distribution of microelements indicated that a considerable portion (68-88%) was bound to the cell constituents, a very little part was solved only in the cytosol and vacuole. More than half of the original vitamins B content has been lost during the general guarantee time (12 months) and the microelements had only little influence on it. Enrichment of yeast cells with iron was accompanied by considerable increase in vitamin B2