B12 contributes to normal homocysteine metabolism and red blood cell formation, to the reduction of tiredness and fatigue, the energy-yielding metabolism, to normal psychological function and the functioning of the nervous system. Vitamin B12 also contributes to the normal function of the immune system.Folic acid (folate) contributes to a reduction in tiredness and fatigue, the normal function of the immune system, normal psychological function, and the processes of normal homocysteine metabolism, amino acid synthesis, cell division and blood formation.

B complex vitamins (B1, B2, B3, B5, B6 & B12) contribute to the reduction of tiredness and fatigue, to normal psychological function and mental performance, energy-yielding metabolism, the regulation of hormonal activity, the functioning of the immune, cardio and nervous systems and the maintenance of normal skin, mucous membranes, vision and red blood cells. B complex vitamins also contribute to the protection of cells from oxidative stress. This ‘oxidative stress’ appears to be a major factor in many human diseases.