Is B12 useful for Langlebigkeit?

Vitamin B12 is essential for nerve function, DNA synthesis, and energy metabolism. Deficiency can mimic aging-related symptoms, but whether B12 promotes longevity is nuanced. Observational studies link low B12 and elevated homocysteine to increased risk of cardiovascular disease and cognitive decline—both factors that can affect lifespan. However, randomized controlled trials have not demonstrated a clear lifespan-extending benefit of B12 supplementation in individuals with normal baseline levels. Genetic variants such as in the FUT2 gene (rs602662) may slightly reduce absorption, but most carriers maintain normal levels. Blood testing before supplementing is recommended. For vegans, older adults, or those with malabsorption, correcting a deficiency is important for healthspan. For well-nourished individuals, high-dose B12 lacks proven longevity benefit. The evidence is mixed: strong observational associations but insufficient interventional data. Safety note: B12 is non-toxic at high doses, but unnecessary supplementation provides no benefit.