Answer:
Vitamins
Step-by-step explanation:
Vitamins are nutrients that the body needs in small quantities for the metabolism to be able to work properly. Vitamins don't have calories and because of that they are not able to provide energy directly. Also, the best source for them is the food but when the body is not able to get enough, people take supplements. According to this, the answer is that the nutrient source that doesn't directly provide energy are the vitamins.