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 ene