Vitamin B12: A cornerstone of cognitive and metabolic well-being in young adults

Abstract

This systematic review investigates the relationship between vitamin B12 levels, biochemical markers, electrophysiological parameters, and cognitive functions, with particular attention to the impacts on obesity in young adults. Vitamin B12 plays a critical role in supporting metabolic and neurological health. This review emphasizes the potential risks associated with B12 deficiency, especially for individuals following restrictive diets such as vegetarianism or veganism. Comprehensive searches were conducted across databases, including Web of Science, PubMed, Scopus, and Google Scholar, encompassing research published from January 2010 to February 2024. The selection process focused on original research, review articles, and clinical studies that examined the correlation between serum vitamin B12 levels, biochemical markers such as homocysteine and methylmalonic acid, and cognitive and metabolic outcomes. The review included approximately 80 high-quality studies. Key findings indicate that low vitamin B12 levels are common among obese individuals, contributing to metabolic disturbances such as insulin resistance, increased inflammation, and lipid imbalances, which can further exacerbate obesity. The deficiency is also linked to compromised cognitive performance, including deficits in memory, executive function, and attention, due to impaired nerve conduction and altered neurotransmitter synthesis. This highlights the interconnected nature of B12 deficiency, obesity, and cognitive health, underscoring the need for targeted interventions. Ensuring adequate vitamin B12 intake is essential for maintaining metabolic balance and cognitive function, particularly in populations at risk of deficiency due to dietary restrictions or obesity. The review advocates for the development of tailored dietary guidelines and supplementation strategies to prevent deficiency and its associated health risks. Future research should focus on establishing causal relationships and evaluating effective intervention methods to support metabolic and cognitive health.