Instant Nutritional Necharges.Nutritional yeast can be particularly helpful for vegetarians and vegans if it has added vitamin B-12, as this vitamin mostly occurs in animal products.Research has shown that S. cerevisiae, the strain of yeast in nutritional yeast, can support the immune system and reduce inflammation resulting from bacterial infection. It may also be helpful in treating diarrhea.Some research suggests that nutritional yeast can combat brittle nails and hair loss. It may also help reduce acne and improve other common skin problems, particularly in adolescence.Nutritional yeast can also support a healthy pregnancy. The United States Preventive Services Task Force recommend that all women who are planning a pregnancy take 400–800 mcg of folic acid a day to prevent congenital abnormalities and support the growth of the fetus.