DaVinci Immune Pro formulas are designed to maximize absorption and utilization of this essential vitamin. Vitamin C in DaVinci Immune Pro is in the buffered Ascorbate form. That buffer helps to prevent the stomach irritation common when supplementing with plain ascorbic acid found in over the counter Vitamin C supplements. Immune Pro formulas also contain minerals and bioflavonoids that help increase the effectiveness of Vitamin C by 50%.