A milligram is a unit of mass in the metric system, equal to one-thousandth of a gram. It is commonly used to measure very small quantities, such as the weight of vitamins, medications, or chemicals. For example, a typical aspirin tablet might contain 500 milligrams of active ingredient, which helps people understand how much they are taking. In everyday life, milligrams are important in fields like medicine and nutrition. When doctors prescribe medication, they often specify the dosage in milligrams to ensure patients receive the correct amount. Similarly, nutrition labels on food products may list vitamins and minerals in milligrams, helping consumers make informed choices about their health.