This dietary supplement has bi-layer tablets with sustained release vitamins. DualTabs Mega Vitamin and Mineral Formula is a revolutionary new concept in multivitamin and mineral supplementation. Each tablet is composed of one layer of fat-soluble vitamins as well as sustained release water soluble vitamins, and another layer of rapid release minerals and digestive aids.The water soluble vitamins are released over a prolonged period of time through the passage in the digestive tract for optimum absorption. DualTabs sustained release bi-layer formula also eliminates the need to take vitamins more than twice daily to achieve peak blood levels of water soluble vitamins over a prolonged period of time. DualTabs eliminate the interaction between incompatible nutrients for maximum stability and quality. Iron is specially coated to minimize gastric disturbance. Sustained release nutrients enhance mineral digestion and absorption.