1,25 dihydroxy vitamin D (1,25(OH)2D) has been shown to regulate the major blood pressure regulating hormone, renin, in the kidneys, and thus acting as an inhibitor of the renin-angiotensin system, which is beneficial since an over-activation of the renin-angiotensin system can lead to hypertension [13,14]. This evidence concerns the gene REN and hypertensive disorder.