Candida yeast can grow out of control for many reasons. One of these reasons is B12 deficiency, but more commonly, this happens when the immune system is not working as well as it should. This yeast can live within the body without causing any problems for a very long time, but when it multiplies unchecked it can lead to fungal infections, vaginal yeast infections, and thrush. It can also produce infections in the sinuses and in the respiratory system. There are some effective Chinese medicine Candida treatments that might help keep infections and yeast at bay.