Excessive levels of vitamin B12 in the body may be associated with an increased likelihood of developing oncological diseases. This conclusion was reached by researchers studying the impact of high doses of vitamin on cell growth processes and the possible development of malignant tumors, as referenced by The Conversation.
According to specialists, vitamin B12 is involved in cell growth processes and supports both healthy and potentially pathological cell structures. This has led to the investigation of whether long-term consumption of high doses of supplements may stimulate the development of already existing malignant cells.
In studies conducted in 2025, scientists recorded that the risks of malignant neoplasms may increase both with a deficiency and an excess of the vitamin. It is noted that some patients with oncological diseases exhibit elevated levels of B12 in their blood. It is clarified that this situation is likely related not to the cause of the disease, but to its consequences: tumor processes may affect liver function, where vitamin-related substances are produced, and also alter the levels of proteins responsible for its transport in the blood.
Specialists emphasize that vitamin B12 remains an important element for the health of the body; however, uncontrolled intake of supplements can be unsafe. Doctors recommend not to self-prescribe high doses and to monitor vitamin levels only under the supervision of specialists.
