Brewer's yeast is made from a one-celled fungus called Saccharomyces cerevisiae and is used in making beer. It also can be grown specifically to make nutritional supplements. Brewer's yeast is a rich source of minerals - particularly chromium, an essential trace mineral that helps the body maintain normal blood sugar levels; selenium; protein; and the B-complex vitamins. It tastes bitter and should not be confused with baker's yeast, nutritional yeast, or torula yeast; all those types of yeast are low in chromium. Brewer's yeast has been used for years as a nutritional supplement. Some studies, but not all, suggest that chromium supplements may help people with diabetes.