What are the molecular links between the various B-vitamins, with particular emphasis on their roles in dementia and psychiatric disorders?
Background: Dementia prevalence is increasing worldwide; some risk factors are considered modifiable such as diet and life-style. Recently vitamin B5 have been found to be deficient in the brains of patients with two of the major forms of dementia, Huntington disease (HD), and Alzheimer disease (AD). Also, interestingly, vitamin B5 was also found to be present at high concentrations in the brain and localizes with myelin in the white matter. Other B vitamins have been also linked to dementia including vitamins B1, B3, B9, B6, and B12. This systematic review will examine the pathway of each B vitamin to investigate the presence of links between vitamin B5 and the other B vitamins, to examine if its deficiency might alter the function of the other B vitamins, to further understand the impact of its deficiency and will also address the diseases associated with the B vitamin deficiencies and their role in dementia. Aims: To conduct a systematic review to answer the research question about the links between the B vitamins and their role in dementia. Methods: Literature search of various search terms using PubMed and Cochran library Results: No putative effect of vitamin B5 deficiency on the other B vitamins was identified in this systematic review, and the evidence for other B-vitamins’ effects in dementia caused by age-related neurodegeneration is not conclusive. Conclusion: additional studies are required to draw a firm conclusion about the effect of B vitamins on dementia. Also, further research is recommended to understand the effect of vitamin B5 deficiency, especially to the brain, and studies to understand its effect on patients with dementia.