Megasorb B Complex 50 by Solgar 50 Tablet The B Complex is made up of several vitamins that work well together to support nervous system health. B Complex vitamins also promote energy metabolism. Each nutrient in the The B Complex is made up of several vitamins that work well together to support nervous system health. B Complex vitamins also promote energy metabolism. Each nutrient in the B Complex performs a unique role in maintaining proper metabolic functioning and is essential for well being.