Vitamin B-Complex and vitamin B12 food supplement B vitamins contribute to normal energy yielding metabolism and the reduction of tiredness and fatigue Vitamin B12 contributes to normal red blood cell formation and has a role in the process of cell division Holland & Barrett B Complex & B12 Tablets contain Vitamins B1 (Thiamin), B2 (Riboflavin), B12, together with Niacin, and Protease - a digestive enzyme which supports the breakdown of proteins. B vitamins contribute to normal energy yielding metabolism and the reduction of tiredness and fatigue. Vitamin B12 contributes to normal red blood cell formation, and has a role in the process of cell division. It also contributes to normal homocysteine metabolism.