Features and benefits Needed for healthy red blood cells. Ideal for vitamin B12 nutritional deficiencies. Additional information Vitamin B12 is essential for the normal function of all our bodies' cells, and plays a critical role in energy metabolism. Vitamin B12 is essential for red blood cell production and is also required for folic acid metabolism. Humans must obtain dietary vitamin B12 from animal foods such as organ and muscle meats. Strict vegetarians who avoid all animal products may develop B12 deficiency.? There is an increased requirement for vitamin B12 in pregnancy, coeliac disease and other gastrointestinal disorders where there may be malabsorption. The elderly and vegans are at particular risk of vitamin B12 deficiency.