Myths vs facts: B12 and allergy

Claims that vitamin B12 causes or cures allergies are not supported by evidence. B12 is an essential nutrient found mainly in animal products. Deficiency can cause fatigue, tingling, and brain fog – symptoms that may be mistaken for allergies. However, there is no strong evidence that B12 supplements trigger allergic reactions, except for rare injection-site irritation. Some suggest B12 lowers histamine or alleviates allergic symptoms, but controlled trials are lacking. The provided context does not contain relevant information on B12 and allergy. Therefore, caution is warranted: if you have genuine allergies, do not rely on B12 supplements; seek medical evaluation. A MyBody-X test can indicate B12 status via biomarkers but cannot diagnose allergies. Evidence: unclear due to absence of direct sources.