PROBLEM TO BE SOLVED: To provide a calcium-containing agent including seawater-derived calcium as principal component, which is made from seawater through adjustment for increase in the composition ratio of calcium with reduction in the proportion of magnesium and sodium, effective as food additive for well balanced ingestion of minerals without degradation in taste, preferably in a liquid state.SOLUTION: The seawater-derived calcium-containing agent includes at least three mineral components of calcium, magnesium, and sodium, having a calcium to magnesium weight ratio (Ca/Mg) of 5 or more.
