The important part of mineral components in the human diet, especially bio-elements magnesium and calcium, is discussed in this paper. The part of magnesium and calcium in the biochemical and physiological processes of the human organism and daily requirement for these elements are presented. Big deficit of magnesium and calcium in the average diet requires the peculiar supplement The excellent sources of these elements are mineral and mineralised waters. The minimal contents of magnesium and calcium in mineral water having to fulfil the part of prophylactic-health functional beverage are presented.