The present invention relates to: a composition for regenerating or repairing
skin damage and / or promoting epidermal
cell differentiation, comprising
calcium lactate as an
active ingredient; and a method therefor, wherein the
skin damage includes that caused by
ultraviolet rays. The present invention induces differentiation of epidermal keratinocytes so as to form a biological barrier and allows the
skin to maintain
moisture on its own, and, as a temporary effect, plays a role in protecting the skin from UV by forming nanoparticles on the surface thereof.