Vitamin B12 is a vital nutrient your body needs but cannot produce on its own. It is involved in producing red blood cells, DNA synthesis, and supporting healthy, functioning nerves. Its role in cell production also makes vitamin B12 essential to supporting stronger hair, skin, and nails. One of vitamin B12's most important jobs in the body is producing red blood cells that transport oxygen throughout our bodies. Most experts agree that the best way to ingest B12 is sublingually, or under the tongue since they are easier to absorb. Liquid drops are the superior form of B12 because they're more concentrated than sprays and absorb faster than capsules, which must first be digested.