2012; Evans et al. 2013). VDD can lead to hypertension, involving the renin-angiotensin system, together with changes in the endothelium and vascular smooth muscle. Mice deficient in 1α-hydroxylase, the enzyme that converts vitamin D into its active form, calcitriol, develop hypertension and right ventricular hypertrophy (Vaidya and Williams 2012; Lucisano et al. 2013; Tamez et al. 2013). Here, REN is linked to Hypertension.