These are purchased directly from Holland and Barrett. Limited stock. What is it? Holland & Barrett Magnesium with Zinc tablets support normal bones and muscles and helps to reduce tiredness and fatigue. Contributes To the Maintenance of Normal Bones Reduces Tiredness and Fatigue Suitable For Vegetarians and Vegans What Are the Benefits of This Supplement? Magnesium contributes to a reduction of tiredness and fatigue, normal energy yielding metabolism, normal functioning of the nervous system and normal muscle function. Zinc contributes to the normal function of the immune system, normal fertility and reproduction, maintenance of normal bones and has a role in the process of cell division.