Folic Acid, Vitamin B12, Vitamin C. Iron contributes to the reduction of tiredness and fatigue. Iron contributes to the normal formation of red blood cells and hemoglobin, , contributes to normal oxygen transport in the body, has a role in the process of cell division, contributes to normal cognitive function. Iron, Vitamin c, Vitamin b6 and Vitamin b12 all contribute to the normal functioning of the immune system.