Recent Advances in the Role of Vitamins in the Prevention and Treatment of Alzheimer’s Disease: A Literature Review

Main objective of this review is critically evaluate the use of vitamins in the safety measure as well as treatments of Alzheimer’s disease (AD) using recent findings of research on both humans and animals. The authors combed through the fundamental literature on association of vitamins (fat-soluble vitamins, water-soluble vitamins and some quasi vitamins) with prevention/treatment of AD to create this narrative review. An online search was conducted in Science Direct, Google Scholar, EBSCO & PubMed, a manual search via catalogues and scientific journals for review the literature regarding the relationship between vitamins and AD and to comprehend the potential mechanisms that may clarify such a relationship. After evaluating the titles and abstracts of the preliminary 500 articles, 350 were chosen. After reading the full texts and accomplishing a supplemental search on "Related citations" and the references of the chosen articles, a total of 282 references were found. The two most frequently mentioned ways that vitamins may affect cognitive function in AD are (1) by influences on a particular plasma amino acid called homocysteine (Hcy) for B vitamins (B6, B9 & B12), and (2) through antioxidant effects, decreasing the free radicals’ contents which can impairment human cells, for vitamins B2, C, D, E, as well as ß-carotene. These theories concerning potential mechanisms are mostly based on preclinical research and findings of links between dementia or cognitive decline and elevated Hcy levels or elevated markers of oxidative stress. The results from current studies show an effectiveness and safety of vitamin supplementation to avert mild cognitive impairment (MCI) as well as the initial phases of AD will likely rely on firstly which metabolic pathways are affected, secondly which vitamins are lacking and could correct the pertinent metabolic flaw, and thirdly, the modulating effect of nutrient-nutrient and nutrient-genotype interaction. Further emphasis on an accurate dietary strategy is needed to recognize the complete prospective of vitamin therapy in avoiding dementia and cognitive function as well as to avoid causing devastation.