Vitamin B4 (Adenine)
"Vitamin B4" is the historical name for adenine, one of the four nitrogenous bases that make up DNA and RNA and the nitrogen-rich core of ATP, NAD, NADP, FAD and coenzyme A. In the 1930s adenine was provisionally classed as a B-complex vitamin; within a decade that classification was withdrawn, because human cells make their own adenine through the de novo purine pathway. The B4 label was dropped, leaving a gap in the B-vitamin numbering. The name has also been applied to other compounds over the years, most often choline, which has its own page on this site.
Vitamin B4 Articles
Vitamin B4 (Adenine) — Benefits Deep Dive
Adenine in cellular energy and ATP, DNA and RNA synthesis, purine metabolism, and its modern status and food sources, in four deep-dive pages.
Read the deep dive →Vitamin B4: History and Discovery
How the B4 label was assigned around 1929–1930, why adenine came to carry it, and why the designation was dropped.
Read the deep dive →