To date, to the best of our knowledge, this is the first study to analyse the association between these two polymorphisms, 25(OH) vitamin D levels and MS, in Mexican patients, which enabled us to examine the interactions between the CYP2R1 gene, CYPB27 gene, and vitamin D levels to assess how these synergisms may influence MS risk. Here, CYP2R1 is linked to myeloid sarcoma.