Composition comprises (i) desalinated sea water, (ii) at least one unicellular alga extract of Tetraselmis, (iii) at least one polysaccharide comprising alginates and alginic acids, brown algae and/or red algae extracts, and (iv) at least one calcium salt, where the sodium chloride concentration of desalinated sea water is less than 10 g sodium chloride per liter of seawater. An independent claim is included a synergistic combination: of at least one calcium salt, where the calcium salt consists of calcium chloride, calcium citrate, calcium nitrate, calcium acetate, calcium hydrogen (bi)carbonate, calcium pyrolidone carboxylate, calcium gluconate, calcium lactate and calcium orotate； of seawater desalination mixture, where the sodium chloride concentration is less than 10g of sodium chloride per liter of sea water (i) an extract of algae Tetraselmis secica, (ii) at least one polysaccharide comprising alginic acid and alginates, and optionally (iii) at least one carrageenan. ACTIVITY : Dermatological. MECHANISM OF ACTION : None given.
