Myths vs facts: B12 and fatigue

A common myth is that vitamin B12 universally fights fatigue, even in people with normal levels. In reality, B12 deficiency is a well-established cause of fatigue, but supplementation only helps if a true deficiency exists. For individuals with adequate B12 stores, high-dose supplements do not provide extra energy. Evidence comes from observational studies and clinical data on pernicious anemia or vegan diets. Many fatigue cases stem from other factors (iron deficiency, sleep disorders, thyroid issues). Blood testing before supplementation is recommended. Marketing claims of B12 as an 'energy booster' for the general population are often exaggerated.