Mega B-Complex from Irwin Naturals is now an advanced absorption formula that features "quick energy" MCTs. It delivers 1,000 mcg of Vitamin B-12 methylcobalamin per serving. B vitamins play a critical role in numerous biochemical reactions throughout the body. They are important for metabolism, energy production and the maintenance of a healthy nervous system. Mega B-Complex is a balanced blend of B vitamins that can help you meet or exceed your daily requirements.