Brewers yeast is high in protein, B-vitamins and chromium. It also contains potassium, zinc, selenium, lithium, magnesium, phosphorous, copper prebiotics and beta-glucans which are anti-inflammatory and immune stimulants. The folate in brewers yeast makes it a popular pregnancy supplement. Brewers yeast contains ergosterol which helps inhibit breast cancer. The galactogogue in brewers yeast has may help increase milk supply when breastfeeding.