This supplement features a higher level of thiamine (vitamin B1). B1 (thiamine) contributes to the normal function of the heartand to normal psychological functionenergy-yielding metabolism and the normal functioning of the nervous system.B complex vitamins (b1b2b3b5b6 & B12) contribute to the reduction of tiredness and fatigueto normal psychological function and mental performanceenergy-yielding metabolismthe regulation of hormonal activitythe functioning of the immunecardio and nervous systems and the maintenance of normal skinmucous membranesvision 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."