A relationship between type 1 diabetes mellitus and vitamin D deficiency has been reported.5, 6 The prevalence of vitamin D deficiency in patients with type 1 diabetes was 15% to 90.6%.7–9 There is evidence that vitamin D is important in the prevention of islet cell death and might be useful in improving the survival of islet cell grafts, and it improves the production of insulin. Here, INS is linked to vitamin D deficiency.