The group of vitamins primarily involved in energy metabolism is the B vitamins. This family of vitamins—including B1 (thiamine), B2 (riboflavin), B3 (niacin), B5 (pantothenic acid), B6 (pyridoxine), B7 (biotin), B9 (folate), and B12 (cobalamin)—plays essential roles in converting carbohydrates, fats, and proteins into usable energy within the body. They facilitate cellular metabolism and are critical for maintaining optimal energy levels, ensuring that the body can efficiently utilize the nutrients consumed for various physiological functions.