Advanced Nutrition by Zahler Advanced Vitamin C Formula 1000+ mg Per Serving Dietary Supplement Feel Better, Everyday Kosher Parve This Product was Manufactured in a GMP Registered Facility Non-GMO Gluten Free Dairy Free Soy Free Vegetarian Friendly Advance Vitamin C Vitamin C is an essential antioxidant that helps support the immune system. Since Vitamin C is water soluble and the body cannot store it, a continuous supply is needed.