Is Vitamin D deficiency implicated in autonomic dysfunction?

Dysautonomia, dysfunction of the autonomic nervous system, presents with heterogeneous clinical features from an imbalanced regulation of the sympathetic and parasympathetic nervous systems. Low Vitamin D levels can explain the heterogeneous clinical features of migraine headaches, cardiac and gastrointestinal dysfunction, and oxidative stress evident in dysautonomia patients. The role of Vitamin D in modulating pain sensitivity has been recently established. However, there is a lack of research and understanding regarding the association between Vitamin D deficiency and autonomic dysfunction. Vitamin D is a neuroactive hormone that modulates autonomic balance, regulating the sympathetic and parasympathetic nervous systems, and has multisystem benefits. The following review explores the literature and addresses the relationship between Vitamin D deficiency and autonomic dysfunction. Overall, this literature review implicates Vitamin D deficiency in autonomic dysfunction and elucidates the potential therapeutic role of Vitamin D in autonomic disorders. PubMed search was performed for English articles from 1996 to 2016. Following keywords: Vitamin D, autonomic dysfunction and orthostatic hypotension, Vitamin D receptor, migraine and traumatic brain injury, Vitamin D, cardiac and gastrointestinal disease, Vitamin D, glutathione, oxidative stress, and serotonin were included. Only articles reporting primary data relevant to the above question were included in the study.