Objective:To evaluate the association of 25-hydroxyvitamin D3[25(OH)D3]and zinc transporter 8 antibodies(ZnT8A) in newly diagnosed type 1 diabetes mellitus(T1DM). Methods:There were 32 newly diagnosed type 1 diabetes mellitus and 100 controls in this study. Clinical data were collected,biochemical parameters,serum 25 (OH)D3 levels and ZnT8A were detected;the relevance of serum 25(OH)D3 and ZnT8A were analyzed. Results:①Serum 25(OH)D3 level was significantly lower in T1DM than that in the controls(P < 0.01). In the vitamin D deficiency group,the prevalence of T1DM was increased,risk odds ratio (OR = 3.16,95% confidence region:3.02~3.31).②From vitamin D sufficient group to vitamin D deficient group,fasting and postprandial C-peptide level were gradually decreased(P < 0.05);the ZnT8A positive rate in vitamin D deficient group was higher than vitamin D sufficient group (P < 0.05).③The ZnT8A positive rate was negatively related with serum 25(OH)D3 concentrations(r = -1.036,P < 0.05). Conclusion:①The serum 25(OH)D3 level in T1DM was significantly lower than that in the controls. The T1DM patients are at risk for vitamin D insufficiencies. ②There was interaction between the serum 25(OH)D3 concentration and ZnT8A.