Vitamin B12: Strategies for enhanced production, fortified functional food products and health benefits

Vitamin B12 is an essential micronutrient that controls many biological functions such as the production of red blood cells (RBCs), DNA synthesis, functioning of nervous system and maintaining the structural integrity of chromosomes. Vitamin B12 deficiency is more prevalent in vegans and being water-soluble, maintaining its adequate levels in the body is a challenging task. Consumption of vitamin B12 fortified functional foods is an effective strategy to minimize its deficiency in human beings, particularly in vegans. Industrial production of vitamin B12 is primarily carried out through microbial fermentation since its production is confined only to bacteria and archaea. Recent advances in metabolic engineering have enabled to engineer microbes with strong promoters, expression vectors, and gene amplification that have transformed microbes into efficient microbial cell factories for the production of vitamin B12. Fermentation process optimization including substrate optimization, precursor supplementation, controlled oxygenation and identifying growth limiting factors have further enabled to adopt effective strategies to enhance its yield. In this review, a comprehensive information on the recent advancements in studies on microbial production, synthesis pathways and absorption mechanism of vitamin B12 along with therapeutic health benefits are highlighted.