Nutritional yeast is sometimes recommended as a dietary supplement to help prevent or support the treatment of anemia, primarily due to its high content of B vitamins, particularly vitamin B12 (when fortified), folate, and iron. Scientific validation for its use is moderate, mainly because certain types of anemia, such as megaloblastic anemia, can result from deficiencies in vitamin B12 or folate. Fortified nutritional yeast can provide substantial amounts of these nutrients, especially for individuals following vegetarian or vegan diets who may be at higher risk for B12 deficiency. Several studies have shown that B12-fortified foods—including nutritional yeast—can help maintain adequate B12 status and prevent deficiency-related anemia in populations with limited dietary B12 sources.

However, not all nutritional yeast naturally contains B12; it must be fortified, so the benefit is specific to fortified products. There is less direct evidence supporting nutritional yeast as a treatment for iron-deficiency anemia, since its iron content and bioavailability are relatively low compared to other sources. Overall, nutritional yeast can be a useful adjunct for preventing certain types of anemia related to B12 and folate deficiencies, but it is not a comprehensive treatment for all forms of anemia, and its effectiveness depends on the fortification status and the underlying cause of the anemia.