The active form of vitamin d, calcitriol, induces a complex dual up-regulation of endothelin and nitric oxide in cultured endothelial cells.

Conclusions: Calcitriol increases the synthesis of both ET-1 and NO in endothelial cells. However, the ET-1 up-regulation seems to be biologically more relevant, as animals acutely treated with calcitriol show slight increases of blood pressure. PMID: 25336523 [PubMed - as supplied by publisher]

http://www.ncbi.nlm.nih.gov/pubmed/25336523?dopt=Abstract

Source: American Journal of Physiology. Endocrinology and Metabolism - October 21, 2014 Category: Physiology Authors: Martínez-Miguel P, Valdivielso JM, Medrano-Andrés D, Román-García P, Cano-Peñalver JL, Rodríguez-Puyol M, Rodríguez-Puyol D, Lopez-Ongil S Tags: Am J Physiol Endocrinol Metab Source Type: research