This nutritional substance provides 2 major types of nutrients: immune factors (i.e. Immunoglobulins, Lactoferrin) and growth factors (i.e. IgF-1 and growth hormone). This nutritional substance has been shown to benefit over 60 known immune and autoimmune disorders. In healthy individuals, this nutritional substance can help maintain well-being and vitality, improve digestion and cellular metabolism, increase endurance and speed recovery time after exercise, and encourage lean muscle growth and fat metabolism. What is this nutritional substance? (Hint: This nutritional substance is vital to a newborn's underdeveloped immune system.)