Vitamins (and minerals) are an essential part of the proper and balanced diet for everyone (men, women, old, and young) and play an extremely important role in metabolism and body processes. They are not a source of energy themselves and do not have caloric value, so they do not impact weight gain. They simply regulate processes, break down food (proteins, carbohydrates, fats) properly, and enable the production of new proteins, sugars, and fats necessary for the functioning and life of the body, tissue regeneration, etc. Without sufficient amounts of vitamins in the body, various disorders can lead to severe diseases.