Provided is a method for stabilizing DHNA or a vitamin contained in a food, a beverage and or like under an environment which can be subjected to natural light or artificial light, e.g. a transparent container, without requiring the use of a container or a packaged article each having a high light-blocking property. Particularly provided is a method for stabilizing DHNA or a virtamin, in which only ultraviolet ray is blocked under an environment which can be subjected to natural light and/or artificial light. Also provided is a method for stabilizing DHNA or a vitamin, in which only ultraviolet ray is blocked by a colorless and transparent film having an ultraviolet ray blocking function. Still also provided is a method for stabilizing DHNA or a vitamin, in which only ultraviolet ray is blocked by a lighting having an ultraviolet ray blocking function.
