VDR and obesity due to melanocortin 4 receptor deficiency: Mutations of the VDR gene and the presence of SNPs may account for variation in individual responses to levels of circulating vitamin D. The overall objective of this study is to investigate the genotypes and allele percentage frequency distribution of four common polymorphisms, FokI, BsmI, ApaI and TaqI, in the VDR gene in healthy Emirati individuals and their association with Vitamin D levels and chronic conditions, including diabetes mellitus, hypertension and obesity.