The important role of vitamins is well known with regard to human health and disease. In this book, we review the effects of vitamins, A, B and C on the structure and dynamics of DNA and RNA. The conjugations of vitamin A (retinol and retinoic acid), vitamin B (folic acid) and vitamin C (L-ascorbic acid) by DNA and tRNA were analyzed. The loading efficacies of these vitamins with DNA and RNA were compared in solution. Vitamins bind nucleic acids via hydrophilic, hydrophobic and H-bonding contacts with vitamin C forming more stable DNA and tRNA adducts. The loading efficacies of these vitamins were from 40% to 60%. Vitamins induce major DNA and RNA structural changes, while biopolymers remain in native conformations.