Vitamin D and Mental Health: From Neurobiology to Clinical Outcomes

Vitamin D has a role to play in brain function, with growing evidence linking its deficiency to a variety of psychiatric and neurodevelopmental disorders. This chapter explores the multifaceted roles of vitamin D in mental health, detailing mechanisms that may contribute to its association with psychiatric conditions. A significant focus is placed on depression, highlighting the uncertainty of whether vitamin D deficiency causes depression or if depression leads to vitamin D deficiency. The role of vitamin D in neurodevelopment is discussed through its impact on schizophrenia and autism spectrum disorders. The chapter also evaluates the effects of vitamin D supplementation on psychiatric outcomes, noting it is not recommended as a first-line treatment for managing or preventing psychiatric disorders. Whether vitamin D deficiency contributes to the onset of psychiatric disorders or is a consequence of them remains unclear, but understanding this relationship is crucial for guiding management approaches.