Origin
A criminal, Dennis and his brother were imprisoned by Judge Smart for their crimes. When his brother died in prison, Dennis swore to seek revenge on the Smart family. Upon leaving prison he acquired Vitamin X, which gave him superpowers, and took part in the Second World War as Vitaman.
Creation
Vitaman was created by Grant Morrison and Yanick Paquette. He made his first appearance in Seven Soldiers: Bulleteer #4.
Major Story Arcs
Seven Soldiers of Victory
Living in London, he encounters Sally Sonic, the daughter of Judge Smart, who, due to her immortality, appears to be permanently a teen. He seduces her by promising they will fight crime together, and slowly begins to manipulate her. He coerces her into getting involved in sex work, sells her for illegal fights, and gets her addicted to drugs. He eventually dies, but not before completely breaking Sally.
Powers and Abilities
Vitaman is superhumanly strong.