Final answer:
Information about a client taking self-prescribed doses of Vitamin C should be recorded in the Intake section of the Nutrition Diagnosis according to the NCP.
Step-by-step explanation:
According to the Nutrition Care Process (NCP), if a client takes self-prescribed therapeutic doses of Vitamin C, this information should be recorded in the Intake section of the Nutrition Diagnosis. The Intake category is used to document information related to the types and amounts of food and nutrients consumed. Noting the use of vitamin supplementation, particularly when self-prescribed, is crucial for a comprehensive nutrition assessment and subsequent planning and monitoring.