Provides magnesium and vitamin B6 which contribute to a reduction of tiredness and fatigue and to normal energy yielding metabolism. These synergistic nutrients also contribute to the normal functioning of the nervous system and to normal psychological function. Magnesium is needed for production of neurotransmitters and some hormones. Low levels may contribute to disturbed sleep, anxiety and symptoms of pre-menstrual syndrome (PMS). Magnesium is the second most abundant mineral in the body and is involved in more than 300 enzymatic reactions in the body. It plays a role in the normal function of muscles and is involved in the maintenance of bones and teeth. It is important for heart health, low levels increase the risk of arrhythmia and pre-eclampsia (and eclampsia) during pregnancy.