Imeth Bindusara

Vitamin D in Depression and Schizophrenia

Started Sept. 17, 2024

Abstract or project description

This literature review examines the global public health concerns of vitamin D deficiency and insufficiency, affecting nearly one billion people. Increasing evidence links vitamin D to the pathophysiology of depression and schizophrenia, with several potential mechanisms proposed. One key pathway involves vitamin D's role in regulating the expression of tryptophan hydroxylase 2 (TPH2), the enzyme responsible for synthesising serotonin in the brain. Given that serotonin imbalances are commonly observed in both depression and schizophrenia, this regulatory function suggests a possible mechanistic link between vitamin D levels and these neuropsychiatric disorders. Vitamin D also plays a crucial role in modulating neurotrophic factors, specifically by upregulating the synthesis of glial cell line-derived neurotrophic factor (GDNF) and neurotrophin-3 (NT-3) while down regulating neurotrophin-4 (NT-4). These neurotrophic factors are well-recognized for their neuroprotective effects in neurodegenerative diseases; however, recent studies suggest that NGF and NT-3 may also contribute to the pathophysiology of depression and schizophrenia. Furthermore, significant negative associations have been observed between vitamin D levels and pro-inflammatory cytokines, suggesting that increased inflammation may play a critical role in the pathophysiology of depression. This relationship highlights the potential for vitamin D to mitigate inflammatory processes, thereby offering insights into its therapeutic implications for managing depressive disorders. In conclusion, the underlying mechanisms are not well understood and further research is warranted on the relevance of vitamin D in the pathophysiology of depression and schizophrenia as well as the effects of vitamin D deficiency on the development of these neuropsychiatric disorders.