Vitamin C is perhaps the most popular vitamin known to man. It is consumed in a supplemental form by millions of people across the world for its antioxidant properties which are well-documented in medical research. Calcium Ascorbate is an optimal nutritional supplement that combines Ascorbic Acid (Vitamin C) with Calcium Carbonate. By combining these two dietary ingredients we have created a buffered source of Vitamin C that will not contribute to gastric irritation in sensitive persons.* From the FDA s website: Some scientific evidence suggests that consumption of antioxidant vitamins may reduce the risk of certain forms of cancer. However FDA has determined that this evidence is limited and not conclusive