Vitamins need to be thrown away when they pass the expiration date, recommends WebMD. The expiration dates on vitamins must be checked regularly, and the vitamins should be stored in a place that is dry, dark and cool.
Vitamins must be stored where they cannot be reached by children, states WebMD. Because some vitamins interact with certain medications, it is important to consult a physician before taking vitamins or other supplements. Some vitamins exacerbate certain medical conditions. Avoid using foreign vitamins that are unregulated, and seek out vitamins that are marked with the NSF International, U.S. Pharmacopeia or Consumer Lab seal.