Myths vs facts: B12 and Abnehmen

The claim that vitamin B12 directly promotes weight loss is a widespread myth. While B12 is crucial for energy metabolism and red blood cell formation, there is no robust evidence from randomized controlled trials that supplementation leads to weight loss in people with normal levels. A deficiency can cause fatigue and weakness, which might indirectly reduce physical activity – but that is not a specific weight-loss effect. Some observational studies have found lower B12 levels in individuals with obesity, but causality is unclear: it may be a consequence of diet or altered absorption, not a cause. Consumer DNA tests (e.g., from MyBody-X) can identify genetic variants (e.g., MTHFR, FUT2) that affect B12 utilization, but these effects are small and do not justify high-dose supplementation without medical advice. Safety note: Very high B12 doses (e.g., >1 mg/day) are generally considered safe, but may rarely cause acne or interact with certain medications. Bottom line: B12 is not a fat burner. Treating a deficiency is important, but weight loss requires a calorie deficit and a healthy lifestyle.