Vitamin B12 and Reduced Fatigue

B12 supplementation is generally well tolerated.

There are rare reports of acneiform and hypersensitivity responses, although these cannot be completely distinguished from reactions to, e.g., excipients.

There are rare reports of acneiform and hypersensitivity responses, although these cannot be completely distinguished from reactions to, e.g., excipients.

Observational studies associate B12 supplementation and higher circulating B12 levels with increased risks of malignancy. However, these findings are inconsistent, and current evidence is insufficient to establish causality, as potential reverse causation remains a major concern.