Scientists are raising new questions about the relationship between vitamin B12 and cancer risk. While deficiency has long been known to increase dangers, recent studies suggest very high levels may also play a role.
Vitamin B12 supports red blood cell production, DNA repair and nerve function. It occurs naturally in meat, fish, eggs and dairy, with some people relying on fortified foods or supplements. Most individuals on varied diets get enough, though vegans, older adults and those with absorption issues may need extra intake.
