“They found that a lack of vitamin D – produced by the body through exposure to sunlight – and exposure to air pollution were implicated, along with occupational exposure to some types of pesticide.
Excessive levels of minerals found in drinking water may be linked to the disease, the research suggested, but the evidence was mixed.”
Air pollution, environmental chemicals, and smoking may trigger vitamin D deficiency: Evidence and potential mechanisms
https://doi.org/10.1016/j.envint.2018.11.052