Abstract: Gut microbiota are a group of bacteria locating in human gut and are interdependent with human body for a long time. Gut microbiota affect body immune function, fat and energy metabolism, endocrine secretion and so forth. The imbalance of gut microbiota is closely related to the occurrence of many chronic diseases and could cause a series of potential health hazards. Exogenous substances, including harmful pollutants and nutrients, can affect health by influencing the intestinal flora. Studies have shown that cadmium exposure can remarkably disrupt the structure and number of gut microbiota, and significantly reduce the number of beneficial bacteria in mice; while vitamin D can regulate the gut microbiota and increase the number of probiotics, and it can change the susceptibility of mice to colitis. The study reviewed the effects of cadmium exposure and vitamin D deficiency or supplementation on gut microbiota, and discussed the feasibility of vitamin D supplementation to prevent and reduce the health hazards of cadmium exposure.