C-B-R Vitamin C/Bioflavonoid Complex 500 tabs from Source NaturalsC B R Vitamin C Bioflavonoid Complex Antioxidant Protection C B R is a complex of vitamin C (ascorbic acid), citrus bioflavonoids, and rutin, a non citrus bioflavonoid. Vitamin C and bioflavonoids occur naturally together in plants, where they provide a synergistic antioxidant effect. Supplement Facts Serving Size: 1 tablet Amount %DV Vitamin C (as ascorbic acid) 500 mg 8. 33 Citrus Bioflavonoid Complex 500 mg Rutin 52 mg Hesperidin Complex 50 mg