Since 1947 Well-Retained Gentle & Non Acidic Immune Support Gluten, Wheat & Dairy Free Kosher Parve Dietary SupplementEster-C Plus is exclusively formulated by Solgar and provides a patented, pH neutral (non acidic) Vitamin C that is gentle on the stomach. The Vitamin C metabolites in Ester-C positively impact the retention of Vitamin C in cells, providing additional benefits. A special manufacturing process is employed to form a unique calcium ascorbate metabolite complex. This well-retained complex yields beneficial antioxidant and immune system support and incorporates natural bioflavonoids and acerola berry along with rose hips fruit powder.