There are plenty of synonyms for the term "nutritional supplement" that you can use. Here are some examples: dietary supplement, nutrient supplement, vitamin supplement, mineral supplement, health supplement, and sports supplement. All of these terms refer to products that complement and enhance the nutrient intake of a person's diet. Nutritional supplements can serve different purposes for different people, such as maintaining good health, preventing illnesses, boosting energy levels, or increasing athletic performance. Regardless of the reason why you use them, make sure to consult with a healthcare professional before taking any supplement to avoid adverse effects or complications.