1. A composition for administration to a human suffering from a magnesium deficiency or hypomagnesemia, or caused them conditions or disorders, and for the prevention of such conditions or disorders, wherein the composition is for oral administration and comprises a hydrated form of magnesium oxide, denoted MgO · (HO) n, wherein n is any value from 0.1 to 2, at a concentration ranging from at least 10 wt. % To at least 95 wt. % Of the total weight of the composition, in admixture with one or both compounds of Mg (OH) and MgO.2. Composition according to claim 1, comprising a hydrate form magnesium oxide selected from the group consisting of:. a. a hydrate of magnesium oxide MgO · (HO) n, where n is any value from 0.1 to 2, and MgO or b. a hydrate of magnesium oxide MgO · (HO) n, where n is any value from 0.1 to 2, and Mg (OH) ilic. a hydrate of magnesium oxide MgO · (HO) n, where n is any value from 0.1 to 2, and Mg (OH), and MgO.3. Composition according to claim. 1, where n is a value from 0.3 to 1.4. . Composition according to claim 1, wherein the concentration of said MgO · (HO) n is selected from the group consisting of: at least 10 wt. %, At least 20 wt. %, At least 30 wt. %, At least 40 wt. %, At least 50 wt. %, At least 60 wt. %, At least 70 wt. % Or at least 80 wt. % Of the total weight kompozitsii.5. Composition according to Claim. 1 which is in the form of a plurality chastits.6. Composition according to Claim. 1, having a specific surface according to BET of 30 m / g to 40 m / D.7. A composition according to claim. 2, further comprising at least one additional active agent, and a pharmaceutically acceptable nositel.8. Composition according to claim. 7, wherein at least one additional agent selected from the group consisting of vitamin D, vita1. Композиция для введения человеку, страдающему от дефицита магния или гипомагниемии, или вызванных ими состояний или расстройств, и для профилактики таких состояний или расстройств, причем композиция предназначена дл
