Vitamin B12 (VB12), also known as cobalamin, is a water-soluble vitamin that is primarily found in animal-derived foods and contains cobalt in its structure. In humans, cobalamin is an essential nutrient with the highest molecular mass (1355.4 g/mol) and the most complex structure among all vitamins. The EAT-Lancet commission recently proposed that achieving healthier diets by 2050 will necessitate a 50% reduction in the consumption of foods like red meat and sugar, coupled with a twofold increase in the global intake of fruits, vegetables, nuts, and legumes. Embracing a diet abundant in plant-based foods while reducing reliance on animal-derived foods offers advantages for both health and the environment. However, it's important to note that a diet low in animal products can elevate the risk of VB12 deficiency. Additionally, VB12 deficiency is most common in patients in elderly and senile age, and it is a worldwide problem affecting about 10–20% of elderly population. According to the latest reports from the World Health Organization (WHO), VB12 deficiency is poised to become a global epidemic and may become one of the most widespread nutritional deficiencies in the future.