what does vitamin b12 do
1 Vitamin B12 is an especially important vitamin for maintaining healthy nerve cells, and it aids in the production of DNA and RNA, the body's genetic material.2  Vitamin B12 also works closely with vitamin B9 (folate) to regulate the formation of red blood cells and to help iron function better in the body. Vitamin B12 is an especially important vitamin for maintaining healthy nerve cells, and it aids in the production of DNA and RNA, the body's genetic material.