Nutrient and Food Drug Interactions - Objectives Identify drugs known to significantly alter fluid or electrolyte balance. Describe how to prevent vitamin deficiencies related to drug therapy. Recognize the multiple causes of diarrhea associated with drug therapy. Describe nutrient –drug interactions involving certain foods, e.g. grapefruit juice. Discuss means of identifying and appropriately treating clinically important drug-nutrient interactions. List drug vehicles that provide clinically important doses of calories and those that provide an insignificant amount of calories.