GNC Mega Men One Daily is a multivitamin that contains 39 nutrients to support men's health. Multivitamins provide important vitamins and minerals that are also found in natural sources or foods. GNC Mega Men One Daily multivitamin contains amino acids to help fuel skeletal muscles, muscle cells, protein synthesis and maintaining your body's nitrogen balance. These multivitamins also have electrolytes to replace those lost through sweat from exercise and help fight muscle cramping. GNC One Daily provides B vitamins which are needed for carbohydrate metabolism and advanced health blends to support the body's immune, brain and men’s health.