The bases - the letters of the genetic alphabet - consist of the four nucleotides mentioned a page or two back: adenine, thiamine, guanine, and cytosine.
Alcoholics can also develop a B-vitamin thiamine deficiency called Wernicke-Korsakoff syndrome which can kill off brain cells and lead to memory problems, amnesia and lack of muscle coordination.
The first vitamin to be isolated and then synthesised in 1936 was thiamine or B1. Deficiency causes beriberi, a disease that can affect both the cardiovascular and the central nervous systems.