One a dayfor normal function of the immune system reduction of tiredness fatigue and normal red blood cell formationlloydspharmacy a z multivitamins minerals food supplement 90 tabletsfolic acid vitamins b12 and c contribute to the normal function of the immune system whilst niacin riboflavin iron and vitamin b6 may help reduce tiredness and fatigue iron also contributes to the normal formation of red blood cells and haemoglobin and normal cognitive function