Background: The purpose of this article is to extend and elaborate on our current understanding of Calcitriol and
Brain Serotonin synthesis; particularly on how the two may be related.
Methods: Using a 2014 study involving clinical trials to extend this hypothesis.
Results: Vitamin D (Calcitriol) activated the gene that codes for Tryptophan Hydroxylase 2, which synthesizes Brain Serotonin.
It also inhibits Tryptophan Hydroxylase 1, which makes serotonin in the gut.