What is the main purpose of a parenteral nutrition regimen?

The main purpose of a parenteral nutrition regimen is to provide nutrition intravenously. This method of delivering nutrients is specifically designed for patients who cannot obtain sufficient nutrition through their gastrointestinal tract, due to conditions such as severe digestive disorders, bowel obstructions, or when they are unable to eat due to surgery or illness.

Parenteral nutrition contains a balanced mix of essential nutrients, including carbohydrates, proteins, fats, vitamins, and minerals, administered directly into the bloodstream. This approach bypasses the digestive system entirely, ensuring that patients receive the necessary energy and nutrients for growth, maintenance, and recovery.

Other options, such as providing nutrition orally or solely supplementing with vitamins, do not reflect the full scope of what parenteral nutrition entails. Additionally, while hydration is an important aspect of patient care, it is distinct from the nutrient provision that parenteral nutrition offers. Therefore, intravenous administration is the defining characteristic of parenteral nutrition, making it the correct answer in this context.