10% Free Dietary Supplement Sublingual Promotes Tissue Growth & Maintenance and is Essential for Red Blood Cell Formation 21st Century...for a Healthier Future21st Century"s Hi-Potency Sublingual Vitamin B-12 (Cyanocobalamin) promotes maintenance and growth of tissue and is essential for red blood cell formulation. Sublingual release vitamins quickly release nutrients into the blood stream under the tongue bypassing the digestive system.