No significant differences were observed in terms of sex, age, smoking habits, alcohol consumption, the proportion of subjects enrolled in winter, mean sunshine duration per day in the recent 3 months, SBP, DBP, TCH, LDL-C, PTH, IL-10 levels in peripheral blood (P-IL-10), and serum ionized calcium levels among the NC, T2DM, and DFU groups (P > 0.05). This evidence concerns the gene PTH and type 2 diabetes mellitus.