Calcium Ascorbate-C. Buffered, Non-Acidic. With Bioflavonoids. 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 create buffered source of Vitamin C that will not contribute to gastric irritation in sensitive persons.