What type of nutrient provides no calories but is essential for regulatory activities in the body?

The correct answer is vitamins. Vitamins are organic compounds that are crucial for various biochemical processes in the body but do not provide calories. They play essential roles in processes such as energy production, immune function, blood clotting, and vision. Each vitamin has specific functions and deficiencies can lead to various health issues, making them vital despite the fact that they do not contribute any caloric value.

In contrast, carbohydrates, fats, and proteins are macronutrients that provide energy (calories) for bodily functions. While minerals also do not provide calories, they differ from vitamins in that they are inorganic substances that serve various structural and functional roles but are not organic compounds like vitamins. Therefore, while both vitamins and minerals are essential, vitamins are the correct answer in the context of the question specifically about nutrients providing no calories yet being crucial for regulatory activities.