NOW Vitamin C Crystals, Ascorbic Acid is a pure, pharmaceutical grade powder that provides antioxidant protection.* Vitamin C is a water soluble nutrient well known for its vital role in the immune system. Vitamin C is also necessary for the production of collagen (a structural protein in connective tissue) and is therefore important for skin, bone, and joint health.* Vitamin C is needed for amino acid metabolism, neurotransmitter synthesis, and the utilization of many nutrients, such as folic acid and iron.* Vitamin C is also a highly effective antioxidant that can help maintain healthy tissues by neutralizing free radicals generated during normal metabolism and exposure to environmental stressors.*