dose

A dose is the quantity of a medication, nutrient, or pathogen to be given at one time, or the total quantity of a medication administered during a specified period of time. In nutrition, the term is usually applied to how much of a specific nutrient is in a person's diet or in a particular food, meal, or dietary supplement. For bacterial or viral agents, dose typically refers to the amount of the pathogen required to infect a host.

In clinical pharmacology, dose refers to the amount of drug administered to a person, and dosage is a fuller description that includes not only the dose (e.g., "500 mg") but also the frequency and duration of the treatment (e.g., "twice a day for one week"). Exposure is defined as the contact with or ingestion of substances, which can lead to a range of clinical presentations. This is in contrast to their interchangeable use in other fields.