Myths vs facts: B12 and Allergie

The question of myths vs. facts about vitamin B12 and allergies is often debated. A common myth is that B12 deficiency causes or worsens allergies. In reality, there is no strong human evidence for a causal link. Some observational studies suggest lower B12 levels in children with atopic dermatitis or asthma, but results are inconsistent and confounded by diet, microbiome, and socioeconomic status. Another myth is that B12 supplements relieve allergy symptoms; no randomized controlled trials support this. Mechanistically, B12 is a cofactor in homocysteine metabolism and methylation, which could theoretically modulate immune function, but this remains speculative. The fact is: confirmed B12 deficiency should be treated, but not with the goal of curing allergies. The overall evidence is weak, based mainly on association studies. Consumers should not rely on B12 supplements for allergy treatment. Suspected allergies require medical evaluation with specific diagnostics (IgE, skin prick test). High-dose B12 is generally safe but unnecessary without indication. The provided context contains no specific data on B12 and allergies, so this answer is based on general medical knowledge.