* Antioxidant Protection * 100% Pure Buffered Vitamin C Powder * GMP Quality Assured * A Dietary Supplement * Vegetarian Product 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.