Generally, no, too much B12 is not known to damage the liver based on current understanding.
According to available information, excess B12 is typically handled by the body in one of three ways:
- Storage: It can be stored in the liver.
- Circulation: It can be present in the blood without causing harm.
- Excretion: It can be excreted from the body.
The reference indicates that "in general, there are no known adverse effects caused by elevated B12." Furthermore, the reference notes the absence of studies investigating potential clinical effects of high B12, implying a lack of concern within the medical community regarding B12 toxicity.
