Various yeast products are made available as commercial food supplements although the need for such sources of vitamins is unclear. Brewers yeast is a rich but variable supplier of vitamins in the B group and provide chromium, mannans and other supplemental products. Adding yeast to a normal diet is unlikely to offer any measurable benefit, although some takers will claim that they feel better. The same benefit can be obtained from standard multivitamin preparations and these will usually be less expensive. There is no evidence that any common yeast product is a more suitable source of vitamins and other needed nutrients than any of the alternative yeasts.
Many disorders of health are claimed to be benefited by yeast preparations. On the other hand some people are allergic to yeast and yeast products such as beer, and they may develop asthmatic or other allergic problems if exposed to yeast in the diet or even in their environment.