VDR and type 1 diabetes mellitus: Prospective cohort studies of at-risk children measured 25OHD levels in infancy and childhood and reported inconsistent findings: the Type 1 Diabetes Prediction and Prevention (DIPP) study (9) and the Diabetes Autoimmunity Study in the Young (DAISY) (10) independently reported lack of evidence, whereas The Environmental Determinants of Diabetes in the Young (TEDDY) study found an association between low serum 25OHD levels and increased risk of islet autoimmunity which was modified by a vitamin D receptor (VDR) genotype (11).