3. Vitamin D and Renin-Angiotensin-
Aldosterone System
The renin-angiotensin-aldosterone system (RAA) maintains
vascular resistance, due to angiotensin II synthesis, and extracellular
fluid volume homeostasis, considering the release
of aldosterone [19]. Studies by different groups, in both
animals and humans, demonstrated that vitamin D decreases
RAA activity [20], suppressing renin gene expression [12].
Vitamin D regulates the genes involved in renin production,
through a cis-DNAelement in the renin gene promoter [1, 21],
downregulating the RAA system.